Diplomatic Calculus in Anarchy: How Communication Matters

22 Pages·2010·0.42 MB·English

AmericanPoliticalScienceReview Vol.104,No.2 May2010
doi:10.1017/S0003055410000158
Diplomatic Calculus in Anarchy: How Communication Matters
ROBERT F. TRAGER UniversityofCaliforniaatLosAngeles
Whenstatescometobelievethatotherstatesarehostiletotheirinterests,theyoftenreorienttheir
foreign policies by realigning alliance commitments, building arms, striking first, mobilizing
troops, or adopting policies to drain the resources of states that menace them. This article
presentsacrisisbargainingmodelthatallowsthreatenedstatesawiderarrayofresponsesthanthechoice
tobackdownornot.Twoimplicationsarethat(1)“cheaptalk”diplomaticstatementsbyadversariescan
affectperceptions of intentions,and (2) war can occur because resolved states decline tocommunicate
theirintentions,eventhoughtheycould,andeventhoughdoingsowouldavoidawar.Themodelrelates
thecontentandqualityofdiplomaticsignalstothecontextofpriorbeliefsaboutintentionsandstrategic
options.Insimulations,thisformofdiplomaticcommunicationreducesthelikelihoodofconflict.
In the fall of 1876, Russia queried Germany as to therefore,alsofailtoexplainthecase.4YetBismarck’s
what its position would be if Russia were to go appraisal was correct: thereafter, Russia reckoned on
towarwithAustria-Hungary.Germanyreplied,as GermansupportforAustria-Hungary.5
delicately as it possibly could, that it could not guar- Inthisarticle,Idescribeabargainingmodelinwhich
antee its neutrality in such an eventuality, and that stateshavearicherarrayofoptionsthantheprevious
“a lasting weakening of Austria would be contrary to literature has allowed. This results in a mechanism of
[German] interests.”1 The German chancellor, Otto information transmission that provides a convincing
von Bismarck, thought that this created a “new situ- explanationforthiscase,and,Ishallargue,represents
ation”intheGerman-Russianrelationship.2Hemeant an essential aspect of interstate diplomacy. The anar-
that Germany had increased Russian expectations chic strategic context can provide less resolved states
aboutGermany’swillingnesstogotowaronbehalfof withadisincentivetomisrepresentingtheirintentions.
Austria, and perhaps decreased Russia’s appraisal of Very often, when states negotiate over important se-
the extent to which Germany would support Russian curity concerns, there is a danger that a threat (or
aimsgenerally. othernoncooperativebehavior)willresultinabreach
Accordingtomosttheoriesofinformationtransmis- in relations, not merely with respect to the issue at
sionbetweenstates,thisshouldhavebeenimpossible. hand, but also with respect to other aspects of the
Germanycommunicateditspositionprivatelythrough relationship. In such cases, states can send “costless”
diplomaticchannels.Thus,Germanelitesdidnotstake signalsabouttheirintentions.Informationisconveyed
their reputation before a domestic audience, nor did by threats because states understand the dangers of
theiractionscarryexplicitcosts,twocommonlyrecog- altering other states’ perceptions of their intentions,
nized mechanisms of information transmission.3 Fur- andyetchoosetothreatenanywaywhentheyaresuffi-
ther, Germany’s noncommittal statements can hardly cientlyresolved.Alternatively,ifforeignpolicychoices
beconsideredtohavesoengageditsreputationbefore areresponsivetoperceptionsofotherstates’intentions
theRussianandinterstateaudiencesthatanyonecould at all, then explicit threats from one state to another,
have believed Germany significantly less willing to whether in public or private, can convey information.
backdownforfearoftherepercussionsofhavingbeen Thus, this article contributes to the literature on the
caught in a bluff. Theories of information transmis- conditionsunderwhichcostlessdiplomaticsignalsare
sionthatrelyonthestakingofbargainingreputations, informative.6
A second result of the model is a path by which
incompleteinformationcanleadtoconflictthatisdif-
RobertF.TragerisAssistantProfessor,DepartmentofPoliticalSci- ferent from the mechanism in other models in the
ence, University of California at Los Angeles, 4289 Bunche Hall, literature. War can occur in some equilibria because
Box951472,LosAngeles,CA90095-1472([email protected]). resolved states decline to communicate their resolve
IamgratefultoMichaelChwe,MariaFanis,ErikGartzke,Mike
Horowitz,RobertJervis,AndyKydd,HelenMilner,BarryO’Neill,
Kris Ramsay, Sebastian Rosato, Ken Schultz, Art Stein, Dessie 4See,forinstance,Sartori(2005).SeeFearon(1995)forananalysis
ZagorchevaandseminarparticipantsattheOlinInstituteforuseful oftheefficacyofcostlessdiplomaticsignals.
commentsandsuggestions,aswellastoBobandJudithTerryand 5AstheGermanAmbassadorwrote,“nothingwasmorenatural”
OrielCollege,Oxford,foraconduciveenvironmentinwhichtowrite. (Schweinitz1927,350–1)thanfortheTsartoexpectaguaranteeof
Ibearresponsibilityforremainingerrorsandomissions. Germanneutrality,andheremainedopenlydisturbedbytheGer-
1Schweinitz (1927, 360). The Russians did not explicitly threaten manresponsefordays(Rupp1941,204;Schweinitz1927,360–364).
Austria,butitwasatthistimethatthesaying,“theroadtoCon- AccordingtotheRussiandiplomatKartsov,theideaofdeclaringwar
stantinopleleadsthroughVienna”(Rupp1941,232)gainedpopu- onAustria“wasabandoned”because“PrinceBismarckforewarned
larityinRussiandiplomaticandmilitarycirclesandmanyRussians that Austria was necessary for Germany for reasons of political
andGermansthoughtthatthetense,ongoingAustro-Russian ne- balance of power and that Germany would therefore not permit
gotiationscouldleadtowar.SeeIgnatyev(1931,391),Rupp(1941, deliveringAustriaadeath-blow”(Rupp1941,297).SeeTrager(2007,
297),Saburov(1929,82),Schweinitz(1927,359),andGrossePolitik, chap.3).
II,54–66,74–9. 6Otherworksonthissubject,inadditiontothosecitedabove,in-
2Bismarck1915,286. clude Guisinger and Smith (2002), Jervis (1970), Kurizaki (2004),
3See,forinstance,Fearon(1994)andKydd(1997). Kydd(2003),Ramsay(2004),andSchelling(1966;1980).
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DiplomaticCalculusinAnarchy May2010
even though they could, and even though this would change is more often intentional. To bring about this
preventthewar.Thiscanoccurwhenonestateishighly sort of change, attempts at communication must suc-
resolved,andbelievesthatanotherisalso,butbelieves ceed in conveying information. That is, they must be
that the other state does not believe that the first is believed,atleastpartially.Thisarticlewillnotaddress
highly resolved. In such cases, if the first state were howsymbolsacquiretheirmeaningsorhowindividuals
to signal its resolve, there would be a high probabil- are initiated into language groups.7 Rather, I assume
ity that the other state would prepare for conflict. To for analytical purposes that a shared and unchanging
avoid this likelihood, the first state declines to con- language exists and ask this second question, namely,
vey its resolve to the other. Sometimes, however, the howitisthatattemptsatcommunicationbyadversaries
second state would have been willing to comply with canconveyinformation.
the first state’s demand in order to avoid war. Thus, In particular, I look at one of the most adversarial
in this situation, resolved states mimic the behavior aspects of relations between states, when one is at-
of unresolved states in order to catch the other side tempting to coerce another through a threat to use
unprepared.Thiscontrastswithothersignalingmodels force.8Here,morethanelsewhere,weexpectcommu-
inwhichitisgenerallyunresolvedstatesthatwouldlike nication to be difficult because the state making the
toimitatethesignalssentbyresolvedstates. threathasanincentivetomisrepresentitspreferences
This second point is similar to results derived from in order to make the threat appear more credible. In
other recent models that have begun to expand the such situations, as Jervis (1970) recognized, analysts
range of state options beyond those conceived of in distinguishpotentialsourcesofinformationthatcanbe
traditionalbargainingmodels.Ritter(2004,chap.2)ar- manipulatedfromthosethatcannot.Thelattercanbe
guesthatstatessometimesmaketheiralliancessecret, believed,whereastheformeronlyconveyinformation
inspiteofthedrawbacksfromthepointofviewofde- incertaincontexts.
terrence,topreventpotentialadversariesfromtaking Withinthecategoryofinformationsourcesthatcan
countermeasures.Slantchev(n.d.)presentsanultima- bemanipulated,somemessagesarecredible,evenbe-
tum game in which rejected offers lead to conflicts in tweenadversaries,becausesenderswouldnotwantto
which each side must choose a level of effort in the misrepresent their preferences although they could.
fighting. Because the optimal effort of states depends When the message causes the sender, in some con-
on each side’s perception of the strength of the other tingencies,toincurcostsasadirectresultofsendingthe
side,statessometimeshaveanincentivetomakeoffers message, such messages are called “costly signals.” In
inthepreconflictstagethathidetheirtruestrength.The game-theoreticterms,thedecisiontosendthemessage
model below reveals a similar dynamic in the context or not has a direct effect on the payoff function of
of costless diplomatic encounters across a wide range the sender. Perhaps the clearest example from inter-
of seemingly disparate contexts, from alliance politics national relations is the decision to build arms. This
tonuclearbrinkmanship. affects the balance of capabilities directly, but if the
The article has four sections. In the first, I locate arms are costly enough,9 it may also send a signal to
the argument in the literature on communication in anadversaryaboutthestate’sintentions.10 Theadver-
internationalrelations.Inthesecond,Iarguethatthe sarymayconcludethatalessresolvedstatewouldbe
strategicoptionsavailabletothreatenedstatesgowell unwillingtopaythosecosts.11
beyond the binary choice to comply or not in tradi-
tionalmodelsofcoercion.Thethirdsectionpresentsa
modelthatallowsstatesthatarethreatenedtoprepare
7Theliteraturethataddressesthesequestionsistoolargetociteeven
for conflicts and to choose themselves to engage in arepresentativesample.Amongphilosophers,theworkofLudwig
conflict. When these preparations are effective, infor- Wittgensteinisthemostwidelyappreciated.Withininternationalre-
mativecostlesssignalingoccursinplausibleequilibria. lations,seeforinstance,FinnemoreandSikkink(1998),Jervis(1970,
139–224),O’Neill(1999),andWendt(1999,313–69).
Thissectiondiscussestheconditions under whichsig-
8SeeSchelling(1966,70–1)forthedefinitionofcoercionassubsum-
naling can be effective, and under which wars occur
ing“deterrence”and“compellence.”ButseealsoMorgan(2003,3)
thatavailablebutunusedsignalscouldprevent.Afinal foradiscussionoftheintimaterelationshipofthesetwofroman
sectiondiscussesimplicationsoftheanalysis. analyticalpointofview.
9If spending on arms does not reach a threshold related to the
possible values states could place on the issue in question, it will
generallybebeuninformative(atleastasacostlysignal).
COMMUNICATION, CONSTRUCTION, AND 10Foradefinitionofintentionsthatissimilartothegame-theoretic
DETERRENCE conceptofastrategy,seeJervis(1976,48–57).Foranotherdefinition
ofintention,seeBratman(1999).
Social aspects of the human world exist in language, 11Itisnotarguedherethatstatesmustdrawthisconclusionwhen
through which they are created, altered, and reified. they observe other states choosing to build arms, but merely that
such a dynamic is plausible and easily grasped. There is a large
Withinthesocialrealm,somecomplexconstructs,for
literature that discusses costly signaling, especially as it relates to
instance, those that would be identified as sources of crisisbargaining.See,forinstance,Fearon(1995;1997),Jervis(1970,
cultural difference, are the products of many agents 28–9),Kydd(1997),Morrow(1989),andPowell(1990).Italsomay
interactingoverlongperiodsoftimeandconsequently beworthnotingthat,asSartori(2005,58)pointsout,although“audi-
encecosts”havebeenmodeledascostlysignals,thisisprobablybest
change only very gradually in general. But other as-
thoughtofasamodelingshorthand(whenvotersarenotmodeled
pects of the social world, such as the “situation” de-
explicitly) for what is really a costless process. See also Ramsay
scribed by Bismarck, change more quickly, and such (2004)andSmith(1998).
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AmericanPoliticalScienceReview Vol.104,No.2
Butmessagesneednotbeassociatedwithdirectcosts ial for costless communication to occur. For instance,
for there to be disincentives to lie, and thus for the Schellingnotedthat“wordsarecheap,notinherently
message to enable to the receiver to learn something credible when they emanate from an adversary....”15
from it. Whether such disincentives exist depends on Fearon, careful not to overstate the case, argued that
the strategic context. Suppose, for instance, that an “itremainsunclearwhethercheaptalkisimportantin
employer wants to give a high-paying position to an international disputes....” His work as a whole sug-
experienced applicant and a low-paying position to gests, however, that, “costless signals... have no ef-
an inexperienced one. If there is no way to verify fect” on international outcomes.16 Many other schol-
whetheracandidateistellingthetruth,thecandidate ars have followed their lead. I show below that the
mayhaveahardtimeconvincingtheemployerthathe preferencesofstateadversariesareinfactsometimes
orshedeservesthehigh-payingposition.Ontheother sufficientlyalignedtoallowcostlesscommunicationto
hand,ifthehigh-payingpositionisforapilotandthe occur.
low-paying one for a flight steward, the candidate’s This distinction between costly and costless signals
statementsabouthisorherhoursofflightexperience mayseemmerelytechnical,withlittlesubstantiveim-
may well be at least partially informative. Misrepre- portance.Thisisnotthecase.Onithingesthequestion
senting qualifications in this case may result in his or of whether diplomacy, particularly that practiced by
herflyingplanes,whichfortheinexperiencedmayre- leaders behind closed doors, can play a role in de-
sultinacrashthathasnegativeconsequencesforboth termining the course of events in a rationalist frame-
employerandemployee.Inthisemploymentexample, work.Macro-leveltheoriesoftheinternationalsystem
therefore,thetwosideshaveinterestsincommon;com- havegenerallyclaimedtoexplaininternationalevents
municationofprivateinformationmaybepossible.In withoutreferencetodiplomaticcommunication.17This
the game-theoretic literature, such signals are called orientationhasreceivedsupportfrommicro-levelthe-
costless because the actions available to agents and orizing of conflict processes, which has suggested (if
the payoffs associated with material outcomes are all not stated outright) that only directly costly activities
unchangednomatterwhichmessageissent.12 suchasmobilizingtroops,buildingarms,andcreating
Models in the economics literature show that the “backdowncosts”canconveyinformation.Asaresult,
maximal degree of precision of credible costless mes- international relations scholarship has neglected the
sagesincreasesastheinterestsofsenderandreceiver studyoftheroleofprivatediplomaticcommunications,
grow more aligned.13 In two-player games, when re- boththeoreticallyandempirically.
lationships are zero-sum, no “cheap talk” communi- Thereareimportantexceptionstothischaracteriza-
cation is possible at all. Understanding the degree to tionoftheliterature,however,andrecentscholarship
which interests are aligned, however, turns out to be has shown a renewed interest in the mechanisms of
farmoredifficultthanitappearsatfirstglance.14 private diplomacy. Sartori (2002; 2005) has demon-
Many scholars of international relations have con- strated that private diplomatic communications can
cludedthatrelationsbetweenstatesaretooadversar- be made credible by the desire of states to maintain
a bargaining reputation, which makes them hesitant
to send misleading signals for fear of being caught
12The term “costly signal” is sometimes used differently from its
in a bluff.18 Guisinger and Smith (2002) combine two
definitioninthegame-theoreticliteraturetorefertocommunication
mechanismsthatrelyonanydisincentivesassociatedwithsending strainsoftheliteraturetoshowthatinthepresenceof
thesignal,whetherdirectorarisingoutofthestrategicinteractionof a reputational mechanism along the lines of Sartori’s,
agents.Becauseanysignalofresolvethatconveysinformationmust democratic selection of leaders results in an endoge-
resultfromadisincentivetounresolvedtypestosendthesignal,all
nousadditionaldisincentiveagainstbluffing.Kurizaki
informative signals must be “costly” in this sense. The staking of
privatereputations,whichconveyinformationbecauseofthe“cost” (2004)showsthatifapubliclythreatenedstatewilllose
ofnotbeingbelievedinthefuture(Sartori2005),andeveryother face by backing down, then it is sometimes optimal
mechanismofinformationtransmissionarecostlysignalsonthisun- forstatestomakeprivatethreats.Suchthreatsdonot
derstanding,butnotaccordingtothewaythesetermsareunderstood
increase the probability that the threatened state as-
inthegame-theoreticliterature.Recentworkinpoliticalsciencehas
signs to the threatener following through, but neither
usedthegame-theoreticterminology.Intheinternationalrelations
literature,seeKydd(2003),Ramsay(2004),andSartori(2005,51). do these private threats cause that probability to go
Inotherliteraturesee,forinstance,GilliganandKrehbiel(1987). tozero.19 Kydd(2003)presentsacheap-talkmodelof
13SeeCrawfordandSobel(1982),FarrellandGibbons(1989),and third-partymediation.20
foranontechnicaldiscussion, FarrellandRabin(1996).Tobetter
understandthedistinctionbetweencostlyandcostlesssignals,itmay
beusefultoconsiderthefollowing.Ifsendingthesignalcoststhe
sender $100 and the receiver of the signal infers something from
15Schelling(1980,150).Elsewhere,Schellingarguesthatwordsused
thesender’swillingnesstopay$100,thisconstitutesacostlysignal.
toframeanissueaffectperceptionsofresolve.SeeSchelling(1966,
Supposethesignalcostsnothingtosend,however,butconveysin-
35–91).
formationthatcausesthereceivertotake$100fromthesender.The
signalmayonlyhaveaffectedthereceiver’sbeliefsbecauseofthe 16Fearon(1997,69).
anticipatedreactionofthereceiverandthesender’swillingnessto 17Forinstance,Mearsheimer(2001);Schweller(1998);Walt(1987);
sufferthereceiver’sreaction.Nevertheless,thisscenariorepresents Waltz(1979).
acostlesssignalbecausethedisincentivetosendamisleadingsignal 18Jervis(1970,78–83),Schelling(1966;1980),andothershavealso
arisesfromthestrategicinteractionofthetwoagentsratherthan argued in favor of a reputational signaling mechanism in private
fromadirectcostoftakingtheactionitself.Thisissoeventhough diplomacy.
theultimateresult—thelossornotof$100—isthesame. 19SeealsoFearon(1997,84).
14SeeAxelrod(1970). 20Ramsay(2004)describesacheap-talkmodelofpublicdiplomacy.
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DiplomaticCalculusinAnarchy May2010
Earlierworkdescribesseveralothermechanismsof Further,inmanycaseswherereputationsmayappear
privatediplomacy.21Schelling(1966,1980)arguedthat to have been staked, the mechanism I propose here
threats sometimes risk an undesired event that nei- representsanalternativeandsometimesmoreplausi-
thersidedirectlycontrols,whichcausesthethreatsto bleexplanationofcommunication.
convey information. The essence of brinkmanship is Themodelinthisarticlecontributestothisgrowing
thatwhenoneclimberwhoisropedtoanothermoves literature by providing a new mechanism of informa-
closertotheedge,heorshemayslip.Bydemonstrating tiontransmissionbetweenstatesthatappliestocertain
a willingness to slip, the climber conveys information systemiccontextsandappealsneithertothecostliness
abouthisorherresolveintheissuebeingnegotiated.22 ofthesignal,nortobargainingreputation.Thetheory
Schelling’sanalysisfocusesonhowengaginginlimited appliesequallytomessagesconveyedinpublicandin
forms of conflict can constitute an implicit threat be- private. It also demonstrates that a similar signaling
cause it demonstrates a willingness to risk even more mechanism is at work in seemingly diverse strategic
costly conflict. Private threats may have a similar ef- contexts, such as nuclear brinkmanship and alliance
fect,however,inthattheydelayresolutionoftheissue bargaining.
and create a crisis atmosphere in which conflict may
be more likely. Schelling’s work bears important sim-
THE STRATEGIC CONTEXT OF ANARCHY
ilarities to the analysis to follow. Here, however, the
emphasis will be on the intentional action of actors Inprominentmodelsintheinternationalrelationslit-
ratherthanthepartlyexogenousdangerofslidingoff erature, the strategic options of the target of a threat
acliffandontheimplicationsofincludingtheoptionto arelimited:itcanstandfirmorconcede.Thisconceptu-
prepareinmodelsoftheconflictprocess.Theanalysis alizationdoesnotcorrespondtotheoptionsandincen-
tofollowalsomakesitclearthatsomeofthedynamics tivesofstatesintheanarchicinternationalcontext.Ifa
ofengaginginlimitedconflictareequallygermaneto statecomestobelieveitcannotachieveitskeystrategic
costlesssignalsandthustoprivatediplomacy.23 aimsthroughitscurrentrelationshipwithanotherstate,
Ofthesemechanismsforprivateinformationtrans- it may choose to alter that relationship. In particular,
mission, the staking of bargaining reputations has re- rather than merely deciding whether or not to back
ceived the most attention. Despite some scholarship down, threatened states must decide how to prepare
that argues to the contrary, I believe the diplomatic– forconflictiftheybelieveabreachwithathreatening
historical record supports the proposition that the state is imminent. In such cases, states often reorient
maintenance of a reputation for being true to one’s theirsecuritypoliciesinordertodrainresourcesfrom
commitments has been an important force in inter- the threatening state, and they also tend to form new
national affairs.24 As in the case of Germany’s tacit alliancesthatarecontrarytothethreateningstate’sse-
threat to Russia in 1876, mentioned above, however, curityinterests.Inaddition,whenthetargetofathreat
important information is often conveyed by costless believesfutureconflictismorelikely,itwillsometimes
diplomacy that cannot be explained by reputational choose to increase arms production, mobilize troops,
dynamics. In this case and in many others, in making or strike first. These decisions are often made before
athreat,policy-makersonbothsideswerenotprimar- the threatening state chooses to back down or follow
ilyconcernedwithbargainingreputation.Rather,Ger- throughonitsthreatandhaveconsequenceswhether
many worried about consequences that would follow ornotthestatesinvolvedultimatelygotowar.25
if,asitexpected, itsprivatethreatwere foundcredible. ToillustratethestrategicchoicesavailabletoTargets,
considertheresponsesofU.S.PresidentKennedyand
Soviet Premier Khrushchev to each other’s threats in
theirJune1961meeting.Putsimply,eachthreatenedto
21Jervis(1970)proposesthreeadditionalmechanismsthroughwhich escalatetowariftheotherdidnotacceptasettlement
privatethreatscouldconveyinformation.First,ifleadersarereticent
oftheBerlinquestionfavorabletohisside.Following
tolieformoralreasons,credibilitymayattachtotheirstatements.
themeeting,Khrushchevrespondedbyadoptinganew
Second, if a country has a stake in the current functioning of the
international system, a reticence to lie may derive from a desire set of policies designed to drain the resources of the
toensurethatstatesdonottoooftendeceiveeachotherbecause United States. On August 1, he “approved most of a
abaselineofhonestcommunicationmayberequiredtomaintain KGB plan to create ‘a situation in various areas of
theoverallsystemicequilibrium.Third,liesmayresultinunwanted
theworldthatwouldfavorthedispersionofattention
“changesintheinternationalenvironment.”Sometimes,ifastate-
mentisbelieved,otheractorsmayactinsuchawaythattheactor andresourcesbytheUnitedStatesandtheirsatellites,
makingthestatementhasanadditionalincentivetofollowthrough and would tie them down during the settlement of a
onthestatement.Forinstance,ifonestateprofesseshostilitytoward GermanpeacetreatyandWestBerlin.”’26Forhispart,
another, the reaction of the second state may make it in the first
state’sinteresttotakehostileactionsithadnotoriginallyplanned
ontaking. 25Worksthatarguethatstatesreacttoperceptionsofintentionsin
22Powell(1988)formalizesthisideainthecontextofinadvertent waysdescribedhereincludeJervis(1976,chap.3),Schelling(1966),
war. Schultz(2001),Schweller(1994),andWalt(1987).Oneworkthat
23Theconstructivistliteraturehasemphasizedtheroleofbehavior arguesagainststateresponsivenesstotheintentionsofotherstates
in creating norms and shaping expectations, interests, and identi- isMearsheimer(2001).Waltz(1979)doesnotargueagainstacausal
ties,buthasnotfocusedonthecommunicationofintentionamong roleforperceptionsofintentions.Rather,hearguesonlyforasep-
adversaries.See,however,DerDerian(1987). arateandindependenteffectofthedistributionofcapabilities.See
24For criticisms of a reputational signaling mechanism, see Jervis Waltz(2003,53).
(1984),Mercer(1996),Morrow(1994),andPress(2005). 26FursenkoandNaftali(1999,138).
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AmericanPoliticalScienceReview Vol.104,No.2
hardasitistoimaginetoday,Kennedybegantotake changemyalliances.”Withthat,thealignmentbetween
the idea of a nuclear first strike more seriously. He thetwocountriesended.32
toldtheJointChiefsofStaffthat“Berlindevelopments The danger of a great power realignment resulting
mayconfrontuswithasituationwherewemaydesire from a general breach in Russo-German relations is
to take the initiative in the escalation of conflict from also the explanation for the information conveyed by
the local to the general [nuclear] war level.”27 Thus, Germany’s statements in 1876 discussed above. Both
because both leaders were unwilling to back down, sidesunderstoodthatevenatacitthreatfromGermany
they considered or adopted policies to prepare for a might lead Russia to form an alliance with France,
conflicttheythoughtmightbeimminent. Germany’s arch rival since the Franco-Prussian war
Alternatively, consider the Japanese strategic cal- six years before. The fact that Germany understood
culus in 1941. In November of that year, the United the danger, and yet chose to tacitly threaten anyway,
StatesdemandedthatJapanwithdrawfromChina.This meantthatGermanyhadeffectivelycommunicatedits
amountedto“surrenderingherpositionasapowerin resolvetodefendAustria-Hungary.33
theFarEast.”28 JapanwasunwillingtoaccedetoU.S. To fix ideas, and to see the relationship between
demands, and, precisely because it found U.S. threats preparation for conflict and communication, consider
credible,decidedtotakeradicalactiontopreparefor the following stylized examples of international con-
the coming conflict. In the hope of demonstrating its textsinwhichcostlesscommunicationispossible.The
resolvetoresist,andofengaginginonlyalimitedwar modelpresentedinthenextsectionisdesignedtorep-
withtheUnitedStates,Japanoptedtodestroytheof- resentthesesituationsinastylizedway.Asthesenar-
fensivecapabilityoftheU.S.fleetatPearlHarbor.29 ratives make clear, signaling dynamics can be similar
Thehistoryofinternationalrelationsisfullofexam- inseeminglydiversestrategiccontexts.
ples of states responding to diplomatic pressure with
Example 1 (External Balancing). A conflict arises
actions that go well beyond a simple refusal to com-
between two states, a Deterrer and a Target, over a
plywithademand.Infact,whereimportantquestions
specific issue. In order to get its way, the Deterrer
of security are concerned, simply declining to comply
would like to signal its willingness to go to war over
with demands is likely the exception rather than the
theissuetotheTarget.TheDeterrerknows,however,
rule.TheJapaneseresponsetoU.S.,British,andDutch
thatiftheissueisparticularlyimportanttotheTarget,
policy in 1941 was exceptional only in scale and deci-
thelattermayformanalliancewithathirdcountryin
siveness.
order to get its way or prepare for a possible conflict.
InresponsetoAustrianthreatsduringtheCrimean
The Target would prefer not to make the concessions
War, Russia took actions it would not have taken
to the third state required to get an agreement, and
otherwise. These included colluding with France and
the new alliance is also likely to have a negative ef-
Sardinia to strip Austriaof northern Italy, tipping the
fect on the Deterrer’s security position, especially if
balance in Germany in favor of Prussia, permitting
the third country is already hostile to the Deterrer.
therevolutioninHungarythatresultedintheAustro-
Threat-makingthereforehasbothanadvantageanda
HungarianAusgleich(insteadofassistinginsuppress-
drawback. The advantage is the increased likelihood
ingtheHungariansasRussiahadbeforethewar),and
thattheTargetstatewillconcedetheissuetotheDe-
declining torenewgenerous offersofRusso-Austrian
terrer; the drawback is the possibility that the Target
cooperation in the Balkans, leading to drastically in-
will“balance”againsttheDeterrerbyformingahostile
creasedsecuritycompetitionintheregionbetweenthe
twocountries.30Morespeculatively,butwithsomejus- alliance. As has been mentioned, this was the princi-
palconcerninGermanrelationswithRussiaafterthe
tice, the historian Norman Rich argues that the Aus-
Franco-Prussian war. Deterrers for whom the issue is
trian threats during the Crimean War resulted in “a
notsufficientlyimportantareunwillingtoincurtherisk
bitterhostilitythatwastoculminateinwarin1914,the
ofsuchabreachinrelationsbymakingathreat.When
destructionofbothimperialhouses,andtheliquidation
oftheHabsburgEmpire.”31 the Target state observes a threat, therefore, it learns
theissueisrelativelyimportanttothethreateningstate.
A particularly common response to dissatisfaction
with another country’s conduct of foreign policy and Example 2 (Internal Balancing). As the name im-
its perceived hostile intentions is the realigning of al- plies,thisscenarioissimilartothelast,exceptthatthe
liance commitments. In 1864, for instance, Napoleon principlestrategicoptionoftheTarget(thethreatening
III wished to use a European conference to revise state’sprincipalconcern)istotransferresourcestoits
the post–Napoleonic Wars settlement of 1815. When militarysectorinorder,oneday,toresistthedemands
Britain,withwhichFrancewascloselyaligned,refused ofthethreateningstate.ThetimingofChina’sdecision
tosupportaconference,Napoleonwasexplicit:“Soit in the 1950s to devote enormous diplomatic and ma-
seemsweshallhavenoCongress.Well!Ishallhaveto terialresourcestothepursuitofnuclearweapons,for
instance,mayhavebeenpartlyaresultofU.S.threats
in the first and second Taiwan Strait Crises. Because
27CitedinPress(2005,5);italicsadded.
28Feis(1950,327).
29SeeGeorge(1991,19)andRussett(1967). 32Mosse(1958,142).
30ForadetailedcomparisonandanalysisofRussianforeignpolicy 33Forananalysisofthiscase,seeTrager(2007,chap.3).Forarelated
beforeandaftertheAustrianthreats,seeTrager(2007,chap.2). argumentonthefollow-oneffectsofalliancerealignments,seeHealy
31Rich(1965,123). andStein(1973).
351
DiplomaticCalculusinAnarchy May2010
such arms production alters the future bargaining re- Ineachofthesenarratives,thedecisionstheTargetof
lationshipbetweenthenations,internalbalancingwill athreattakeswhenitmeanstoresistthedeterring(or
often constitute a significant long-term drawback to compelling) state’s demands have a negative impact
threat-making. on the Deterrer’s utility. If the Target chooses either
internal or external balancing, the Deterrer’s utility
Example 3 (First Strike). If a Deterrer threatens a
willbenegativelyaffectedevenifitchoosesnottogo
Target,themilitaryandstrategiccontextmaybesuch
to war. This is true when the increased capabilities of
thatiftheTargetisunwillingtobackdownandbelieves
the Target increase the likelihood that the Target will
theDeterringstateisalsosufficientlyunlikelytoback
decidetogotowaritself,andmayalsobetruewhenthe
down,theTarget’sbestoptionistostrikefirst.Thiswas
Targetwillnotcontemplatewarinthenearterm.Inthe
thesituationforJapanin1941.Itwasalsoaworryfor
contextofRusso–Germanrelationsin1876,Bismarck
U.S.PresidentKennedyduringtheCubanmissilecrisis.
wasexplicitonthispoint.EvenatacitGermanthreatto
HerecognizedthataU.S.threattodestroythemissiles
Russia,hearguedinoneforeignpolicycircular,“could
inCubainfourdayscouldresultinaSovietthreatto
induce [the Tsar] to conclude flawed resolutions and
takeactioninthreedays,aswellasfurtherescalations
alliancesthatwouldbeverydisadvantageousforboth
that could result in nuclear war in that time frame.34 sides.”36 A Franco-Russian alliance would have had
In such military-strategic contexts, therefore, threat-
consequences for Germany whether or not the Ger-
makingonceagaininvolvesatrade-offsimilartothat mansbackeddownin1876.37
inExamples1and2.Threatsincreasethechancethata
InternalandexternalbalancingonthepartofaTar-
stategetswhatitwantswithrespecttotheissueathand,
get negatively affects the Deterrer’s expected utility
but can also create a danger that the threatened side
from peace because it changes the balance of power
will begin an unwanted military conflict. Once again,
betweenthem.Ifthetwocountriesareinvolvedinan-
thewillingnessoftheDeterrertoincursuchariskcan
other crisis in the future, the weaker relative position
causethethreattoconveyinformationtotheTarget.
of the Deterrer will usually mean that it is less likely
to get its way and more likely to fare badly if conflict
Example 4 (Too Costly Deterrence). Faced with a
should actually break out. Thus, if future crises are
threat,theTargetmightconsideradoptingpoliciesthat
of the sort described here or, for example, in Fearon
woulddeterthethreateningstatefromattacking.Such
(1994, 1997, 1998), Schultz (1998, 2001) or Slanchev
activities, for instance mobilizing forces on a border,
(2005),theDeterrer’sexpectedfutureutilitydecreases
maybetoocostlytosustainforlong.Ratherthanmain-
in the capabilities of its adversary.38 Although there
tain a high level of preparation, therefore, the Target
may be some contexts in which states are indifferent
statemightprefertogotowar.Powell(1993)analyzesa
totheincreasingcapabilitiesofanadversary,theywill
strategiccontextthatleadstoasimilardynamic.From
moreoftenviewsuchdevelopmentswithunderstand-
the perspective of diplomatic signaling, if we think of
ableconcern.
theTarget’sdecisionasprecedingtheDeterrer’sdeci-
Inthemodeldescribedbelow,weallowforthepos-
siontogotowarorbackdown,thedangerofsuchan
sibilitythattheTargetofathreat,havingmadecostly
outcomeplaysasimilarroletotheriskofafirststrike
preparationsforwar,mightchoosetobeginone.This
inExample3.
results in a concrete risk to the coercing state of ap-
Example 5 (Resource Drain). Other reactions that pearingtomenacetheotherstate.Evenifthecoercing
statesmayhavetothreatsalsohavelong-termconse- state backs down, the other state may make prepara-
quencesforthethreateningstate.AstheSovietUnion tionsforwarandchoosetofightone.Moregenerally,
didfollowingtheViennameeting,forinstance,astate however, we might think of the preparations of the
may choose to drain the resources of another state in Target negatively affecting the coercing state’s utility
order to get its way on a particular issue. As in Ex- becauseoftheeffectofpreparationsonthebalanceof
amples1–4,theriskthatathreatenedstatewilladopt power, even when the coercing state backs down and
such a course provides a disincentive to less resolved thesidesarenotinimmediateconflict.
states to signal their willingness to engage in conflict
oversuchacontentiousissue,makingcommunication
possible.
Example 6 (Mobilization). Whenathreatenedstate 36GrossePolitik,v.II,p.37.
declines to back down and believes conflict likely, it 37Note that Russia elected not to attack or explicitly threaten
mayelecttomobilizeitstroops.Withthecostofthemo- Austria-Hungary and that Russia also did not pursue an alliance
withFranceatthistime.TheFranco-Russianalliancecameabout
bilizationpaid,thechoicetogotowarlooksmoreat-
15 years later, after much intervening history, including Russia’s
tractivetothemobilizedstatethanithadpreviously.35 declaredfrustrationwithGermanpolicyintheCongressofBerlin,
Ifweallowforthepossibilitythatthemobilizedstate theAustro-Germanallianceof1879(directedpartly,andonlypartly
willgotowar,weonceagainhaveatradeoffforstates secretly,againstRussia),andtheGermanfailuretorenewtheRein-
suranceTreatywithRussiain1890.
that consider threat-making, and this again results in
38Kydd(2005)isapartialexceptionbecauseincreasedrelativeca-
thepossibilityofinformativesignals.
pabilitiesofanadversarymayonoccasionmakeitmoretrustingand
therebyresultinanetimprovementofathreateningstate’sexpected
utility.Wecouldalsoconsidermultistateinteractionsinwhichthe
34MayandZelikow(2002,43–4). increasedcapabilitiesofanadversaryarebeneficial,butthereverse
35Slanchev(2005). isofcoursethemoreusualcase.
352
AmericanPoliticalScienceReview Vol.104,No.2
COMMUNICATION IN ANARCHY
FIGURE1. StagesoftheGame
We now turn to a formal model of coercion in which
weallowforthepossibilitythatthreatenedstatesmay Deterrer
decidetotakeactionsthatgobeyondstandingfirmor First stage Makes a costless threat or acquiesces
backing down. In the model, there are two players, a
Deterrer or threatening state and a Target or threat- Target
enedstate.Theplayersareindexedbyi ∈I ≡{d,t}. Second stage Decides (1) whether to take the action in
Themodelbelowisdifferentfrompreviousmodels question and (2) whether to prepare for
in the international relations literature in two impor- conflict
tant respects. First, the Target can chose to prepare
for conflict when it believes it is sufficiently likely, or Deterrerand Target
reorientitsforeignpolicyinotherwaysthatarehostile
Third stage Each decides whether or not to go to war
totheinterestsofthethreateningstate.IftheDeterrer
takes a threatening posture, and if the Target’s costs
of war are sufficiently low relative to the importance
of the issue in question, the Target may be convinced actionsets,thesequenceofmoves,andplayerutilities
totakethesesortsofmeasures.Second,inadditionto are all unchanged. If the initial communication stage
the Deterrer having the option to attack the Target, is important at all, therefore, it is only because the
theTargethastheopportunitytoattacktheDeterrer. Deterrer’s message affects the Target’s beliefs about
Having prepared for war, the Target may opt for it the Deterrer’s intentions. This is possible in equilib-
even if the Deterrer does not. Because the Target’s riumwhentheDeterrerisawareoftheconclusionsthe
actions may lead to an outcome that is even worse Target will draw from a particular messaging strategy
foranunresolvedDeterrerthanthepeacefuloutcome of the Deterrer (and thus also aware of how these
wheretheTargetisundeterred,aresolvedDeterrerhas conclusions will likely affect its actions), and yet the
anincentivetomakethreatsvis-a-visaparticularissue Deterrer’sbestoptionisneverthelesstousethatvery
thatlessresolvedstateswouldbeunwillingtomake.As messagingstrategy.WerestrictattentiontotheDeter-
Ishowbelow,thisdynamiccausesthreatstobemean- rer’sdecisiontothreatenornot,whichwerepresentby
ingful even though no direct cost is associated with themessagem∈M≡{0,1}.Weshallinterpretm=1
makingthem.Onegeneralimplicationofthemodelis asapromisetotakeviolentactioniftheTarget takes
thereforethatifstatesrespondatalltoperceptionsof a particular action, as well as a promise not to take
other states’ intentions in formulating foreign policy, violentactionintheeventtheTargetcooperates.
thenaverbalthreatmadebyonestateagainstanother, In the second stage, the Target has two decisions
whetherinpublicorprivate,canconveyinformation. tomake:whethertotaketheactioninquestionornot
Followingothermodelsintheinternationalrelations (choosinga ∈A ≡{0,1}),andwhethertopreparefor
1 1
literature,weshallsupposethereisabargainingspace conflict(choosinga ∈A ≡{0,1}).IftheTargettakes
2 2
X≡[0,1] such that the Deterrer prefers outcomes theaction,settinga =1,itunilaterallymovesthesta-
1
closer to 1 and the Target outcomes closer to 0. The tusquotos−(cid:1),towarditsidealpoint,where(cid:1)∈(0,s].
statusquoatthebeginningofthegameiss∈X.Players If the sides remain at peace, this will then be the bar-
havevonNeumann–Morgensternutilityfunctionsde- gainingoutcome.Then,inthethirdstage,theDeterrer
finedoveroutcomesinthebargainingspace,x∈X,and andTargetdecidewhetherornottogotowarbychoos-
whatevercostsoffightingandpreparationforconflict ing r ∈R ≡{0,1}, where 1 represents conflict initia-
i i
theplayerspay,c.Specifically; tion. First, the Deterrer chooses r . If r =1, conflict
i d d
occurs;ifnot,theTargetchoosesr.Waroccursifeither
u (x)=x−c t
d d side opts to begin one; both sides must choose peace
and toobtainthatoutcome.Weletrrepresentanindicator
variable that equals 1 when the sides go to war and 0
ut(x)=1−x−ct. otherwise.Thus,r=1ifandonlyifri =1forsomei.
Ifthesidesshouldfightawar,theDeterrerwillwin
Thus, players have risk-neutral preferences over out-
the war with common knowledge probability p(a ),
comesinthebargainingspace.Weassumethisbecause 2
and is then able to choose its ideal outcome in the
itsimplifiestheexpositionwithoutsubstantivelyalter-
bargainingrangeX.Similarly,iftheTargetshouldwin
ing the key points of the analysis. The costs players
the war, it may choose its ideal bargaining outcome.
pay in the game, c and c, will be defined below as
d t
Weassumethatoneofthetwosideswillwinthewar.
functionsofothervariablestoreflecttheoutcomesof
When the Target prepares, the chances that it wins a
player actions during the game, so that, for instance,
warmayincrease:1−p(1)≥1−p(0)⇔p(0)≥p(1).
the players do not pay a cost of conflict when no war
WeshallmodeltheTarget’scostsofwarandprepa-
is fought. (They may still pay a cost of preparing for
rationasconsistingofseveralcomponents.Ifthesides
conflict,however.)
go to war, the Target’s war costs are η ∈[η,η]≡(cid:3),
Figure 1 depicts the stages of the game. It begins t t t t
withtheDeterrer’sattempttoinfluencetheTargetby whereη >0andηtisprivateinformationoftheTarget.
t
sendingacostlesssignal.WhatevermessagetheDeter- IftheTargetchoosestoprepare,itincurssomeprepa-
rersends,thegamethatfollowsispreciselythesame; ration costs, k ≥0, whether or not a war is fought,
t
353
DiplomaticCalculusinAnarchy May2010
but reduces its costs of conflict by β ∈[0,η). Thus, Deterrer options in the first stage × 4 Target options
t
preparations imply an increase in the sunk cotsts that inthesecondstage×3terminalnodesineachStage3
theTargetpayswhetherornotitgoestowarandade- branch).
creaseinthevariablecostsassociatedwiththeconflict Tomakethesignalingprobleminteresting,weshall
itself.(Wemakenoassumptionabouttheneteffectof make severalassumptions about payoffs.First,weas-
preparationsontheoverallcostofconflict.)Thus, sume the Deterrer prefers not to go to war when the
Targetcomplieswithitswishesbynottakingtheaction,
ct(a2,r,ηt)=kta2+r(ηt−βta2). and that there is a possibility the Deterrer would be
willingtofightiftheTargetdidnotprepareandtookthe
We take a similar approach to modeling the Deter-
actioninquestionandapossibilitytheDeterrerwould
rer’s costs, but we suppose the Deterrer has already
notbewillingtofightinthiscase.Thisisequivalentto
madeanyrelevantpreparationsforconflictanddonot
modeltheDeterrer’schoiceofpreparationsexplicitly. s>p(0)−c (1,η )>s−(cid:1)>p(0)−c (1,η ). (1)
For simplicity, we suppose the Target’s preparations d d d d
do not affect the Deterrer’s costs of conflict—only its Second, we assume the Target prefers peace when it
probabilityofvictory.Thus, takes the action in question and does not prepare to
its most preferred war outcome and that there is a
cd(r,ηd)=rηd, possibility the Target would prefer a prepared war to
where η ∈[η ,η ]≡(cid:3) , η >0, and η is private in- accepting the initial status quo and a possibility the
d d d d d d Targetpreferstheinitialstatusquotoapreparedwar.
formationoftheDeterrer.Bothsourcesofprivatein-
Thisisequivalentto
formation are independently distributed according to
thecontinuous,strictlyincreasing,commonknowledge 1−s+(cid:1)>1−p(1)−c(1,1,η)>1−s>1−p(1)
t
distributionfunctions(cid:5) . t
Thus,theDeterrer’suηtiilitydependsonthebargain- −c(1,1,η). (2)
t t
ing outcome, whether the players go to war, and the
Similarly to other models of coercion, these assump-
Deterrer’s type, whereas the Target’s utility depends
tionsimplythattheDeterrer’smostpreferredoutcome
on thosesamefactors and alsoon whether or not the
occurs when the Target complies with the Deterrer’s
Targetchoosestoprepare.Therefore,weshallwritethe
players’utilityfunctionsasu (x,r,η ):X×R×(cid:3) → wishesbynottakingtheactioninquestion(andalsonot
R and u(x,r,η,a ):X×Rd×(cid:3) ×dA →R.39 Subdsti- attacking the Deterrer). The Target’s most preferred
t t 2 t 2 outcome occurs when it takes the action in question,
tutingthecostfunctionsintotheplayerutilityfunctions
does not prepare for conflict, and the Deterrer does
yieldsthefollowingutilitiesforpeace:
notattack.Playersarewillingtogotowarwhenthey
u (s,0,η )=s−(cid:1)a consider the costs of war to be low relative to their
d d 1
evaluation of the issues at stake and their chances of
ut(s,0,ηt,a2)=1−s+(cid:1)a1−kta2. victory.41 An example of parameters satisfying these
assumptionsisshowninFigure3.Thefigurealsorepre-
Similarly,theplayers’expectedutilitiesforwarare40
sentsthemodelintermssimilartothoseusedinFearon
Eu (r=1|a ,η )=p(a )−c (1,η )=p(a )−η (1995)andcanusefullybecomparedtoFigure1ofthat
d 2 d 2 d d 2 d
paper.
Eu(r=1|a ,η)=1−p(a )−c(a ,1,η) ThepreparationsoftheTargetmayormaynothave
t 2 t 2 t 2 t
aneffectontheTarget’scostsofconflictandtheplay-
=1−p(a )−η +βa −ka .
2 t t 2 t 2 ers’ probability of victory. We shall say that prepara-
tions are effective if and only if k >0, p(0)>p(1),
The formal structure of the game is shown in Fig- t
and [(1−p(1))−(1−p(0))]>k −β. The last con-
ure2.WhicheverchoicetheDeterrermakesinthefirst t t
dition states that the Target prefers a prepared to an
stage, the Target has the four Stage 2 options shown
unpreparedwar,orinotherwords,thattheoverallin-
in the figure. Whichever of these the Target opts for,
creaseintheTarget’scostsasaresultofpreparation(if
thesameStage3structureshownfollows.Asthefigure
preparingdoesinvolveanetincreaseincosts)mustbe
shows, the players’ utilities over the Stage 3 terminal
outweighed by the benefit of the increased likelihood
nodeoutcomesdependontheTarget’sStage2choice.
of victory. We shall say preparations are ineffective if
Thefullgametree,therefore,has24terminalnodes(2
k =β =0 and p(0)=p(1).42 Note that in Figure 3,
t t
preparationsareeffective.
39NotethatalthoughtheTarget’schoiceofpreparationdoesnot
affecttheDeterrer’sutilitydirectly,itdoesaffectthelikelihoodof
outcomes(victoryanddefeat)overwhichtheDeterrerhasdifferent 41Here,playersareuncertainabouteachother’scostsofconflict.
preferences. Wemightalsoconsideramodelinwhichplayersareuncertainabout
40So long as player utility functions are bounded, we can de- theimportanceoftheissueinquestiontotheotherside.Amodelof
rive these expected utilities without assuming risk neutrality over thisform,whichgeneratesresultssimilartothosepresentedbelow,
bargainingoutcomesbysettingud(1,0,ηd)=ut(0,0,ηt,0)=1and canbefoundinTrager(2007,chap.3).
ud(0,0,ηd)=ut(1,0,ηt,0)=0 without loss of generality. Because 42Theeffective/ineffectivedistinctiondoesnotexhaustallregionsof
thesides’warutilitiesdonotdependonwhichsidechooseswarin theparameterspace.Weshallnotanalyzecaseswherepreparations
thethirdstage,theorderofplayerchoicesinthisstagewillhaveno impacttheprobabilityofvictorybutarenotcostlyorarecostlybut
substantiveimpactontheanalysis. donotaffectthechancesofvictory.
354
AmericanPoliticalScienceReview Vol.104,No.2
FIGURE2. FormalStructure
1stStage 2ndStage
Deterrer Target
(Don’t (Threaten)
Threaten)
3rdStage
Deterrer
(Don’t (Attack)
Attack)
Target
(Don’t (Attack)
Attack)
FIGURE3. PlayerUtilitiesSatisfyingModelAssumptions
High cost Target’s
Low cost Deterrer’s expected utility from expected utility from a
conflict when the Target does not prepare prepared conflict
High cost Deterrer’s expected
utility from conflict when the Low cost Target’s expected
Target does not prepare utility from a prepared conflict
Deterrer’s peace utility if Target’s peace utility if it takes
the Target takes the action the action and does not prepare
DDetterrer’’s peace uttiilliitty TTargett’’s peace uttiilliitty
at the status quo at the status quo
355
DiplomaticCalculusinAnarchy May2010
Equilibria with Ineffective Preparations over the issue in question than the Target had previ-
ously thought. (We shall see that, in this equilibrium,
We can now ask whether, in such a strategic context,
thissuppositioniscorrect.)RealizingthattheDeterrer
theTargetcanlearnfromthecostlesssignalssentbythe
is more likely to follow through, the Target is more
Deterrer.Commonly,incheaptalkgames,signalerscan
likely to decide that the issue is not worth risking a
conveyinformationthatdoesnotinfluencethecourse
fight over and to back down. If the Target’s costs of
ofevents.Ifcommunicatedinformationwillnotinflu-
war are sufficiently low relative to the value it places
ence actions, it makes little difference to the receiver
on the issue, however, the Target may decide not to
oftheinformationwhetherornotheorshebelievesit
back down and to make costly preparations for war.
to be true. In these equilibria, signals are informative
TheTarget’sdecisionmaybeadifficultonebecauseon
butnotinfluential.Weshallfocusonwhetherequilib-
the one hand, preparations such as alliances, building
ria with influential signals can exist. In such equilib-
arms,orstrikingfirstmayprovideadditional security,
ria,therearesignalsthatincreasetheprobabilitythat
butontheotherhand,suchactionscarrytheirownad-
the Target both does not take the action in question
ditionalcosts.BecausetheTarget’spreparationsaffect
(a =0) and does not attack the Deterrer (r =0).
1 t itsowncalculations about therelativebenefits ofwar
Let q(m)=Pr(a =0,r =0|m) be the probability
t 1 t andpeace,havingprepared,itmaydecidetoattackthe
theTarget’sstrategysatisfiesa =0,r =0givensignal
1 t Deterrer.
m induced by the players’ strategies and beliefs in a
In the first stage, in deciding whether or not to
particularequilibrium.
threaten,theDeterrerunderstandsthesedynamics.If
theDeterrer’scostsofwararehighrelativetothevalue
Definition. Anequilibriumisinfluentialifthereexist itplacesontheissueinquestion,theneventhoughby
signalsm(cid:6) (cid:7)=m(cid:6)(cid:6) playedwithpositiveprobabilityinthe threateningitstandsabetterchanceofgettingitsway,
equilibriumsuchthatq(m(cid:6))>q(m(cid:6)(cid:6)). it will not be willing to make a threat. This benefit to
t t
threatening does not outweigh the increased risk of a
IftheTarget’spreparationsdonotaffectitsprobabil- breach in relations with the Target and the attendant
ityofvictoryortheplayers’costsofconflict,theDeter- increased risk of a costly conflict. Thus, the Deterrer
rer’scostlesssignalscannotconveyinformationtothe willonlybewillingtothreatenifitisrelativelyhighly
TargetinawaythatinfluencestheTarget’sactions;no resolved.This,inturn,impliesthatoursuppositionthat
influential equilibrium exists. If preparations have no theTargetlearnsfromthethreatiscorrect.44
effectonplayerutilitiesoveroutcomes,thenthismodel Aprincipalobstacletoinfluentialcheaptalksignals
is very similar to others in the international relations is the incentive that unresolved types have to mimic
literature.Insuchcases,thereasoninformativesignal- the signals sent by resolved types. In other models in
ingisimpossibleiswellunderstood: thereisabenefit the literature, unresolved types have every incentive
to being thought willing to fight and no drawback.43 tomimicbecausetheycanalwaysbackdownanden-
Therefore,theDeterreralwaystriestosendthesignal sure themselves of an outcome they like just as well
that will most convince the Target of its resolve, but astheoneinwhichtheymakenothreat.Inthemodel
because that signal is sent in every case regardless of described here, however, there may be a danger that
whether it corresponds to the truth of the matter, the the Target will respond to a threat by preparing for
Targetlearnsnothingfromit.Proposition1expresses war and, having done so, launch a strike of its own.
thisformally. When this is possible, low-resolve types face a risk in
misrepresenting their levels of resolve by mimicking
Proposition 1. If preparations are ineffective, no in- thebehaviorofhigh-resolvetypes.45
fluential perfect Bayesian equilibrium exists (in pure
strategies).
44As described, the logic mayappear circular. But note thatit is
circular only in the way that the logic of any truly strategic Nash
Influential Equilibria equilibrium(whereplayers’optimalactionsaredependentuponthe
actionsofotherplayers)mustbecircular.
When preparations have an effect, in some cases in- 45Inthemodel,theTargetcantakeanactionthatshiftsthebar-
fluential equilibria exist in the model. To understand gainingoutcomeinitsfavorby(cid:1)ornottakethataction.Asaresult,
theTargetsometimespreferstogotowarbecausetheshiftinthe
how these equilibria function intuitively, suppose the
bargainingoutcomeisnotsufficienttocauseafullypreparedTarget
Deterrer makes a threat and the Target learns from
topreferpeace.IfitwerefeasiblefortheTargettotakeanaction
thisthattheDeterrerismorelikelywillingtogotowar unilaterallythatmovedthebargainingoutcomesufficientlyfurther
towardtheTarget’sidealpointfollowingpreparationsforconflict,
however,andifweallowedforthispossibilityinthemodel,then
the Target would never choose war in equilibrium and influential
43Thelogichereisonlyslightlymorecomplicatedbecause,unlike signalingwouldbeimpossible.Theassumptionofafixedactionne-
thesituationinmostmodelsintheliterature,theTargetalsodecides gotiatedoverbythestatesisprobablyreasonableinsomecasesand
whetherornottogotowarlateron.TheproofofProposition1must notinothers.Evenifweweretochangethemodeltoallowforan
also demonstrate, therefore, that no influential equilibrium exists increasein(cid:1)followingpreparations,however,influentialsignaling
inwhichresolved,threatenedTargetsdeclinetotaketheactionin wouldstillbepossibleifwerelaxedtheassumptionofriskneutrality
question,therebycommittingthemselvestofightingawar.Ifsuch overbargainingoutcomes.Moregenerally,foralternatebargaining
adynamicwerepossible,lessresolvedDeterrersmightdeclineto protocols,influentialsignalingwouldbepossibleaslongasTarget
threaten,resultingininfluentialsignaling.AstheproofofProposi- typeswithhigherexpectedvaluesforwartakeactionsthatimplya
tion1intheAppendixdemonstrates,however,thiscannotoccur. strictlyhigherlikelihoodofconflict.Thisisanassumptionoraresult
356