Capability, Credibility, and Extended General Deterrence

Abstract

Deterrence theory suggests that extended general deterrent threats are likely to be more effective when a potential challenger views them as capable and credible. When states sign formal defense pacts, they are making explicit extended general deterrent threats. Thus, the population of defense pacts allows us an opportunity to judge the efficacy of extended deterrent threats with different characteristics. We find that defense pacts with more capability and more credibility reduce the probability that a member state will be a target of a militarized dispute. We also find that states can affect the capability and credibility of their extended deterrent threats through alliance design. Members of defense pacts that include higher levels of peacetime military coordination are less likely to be attacked. This analysis provides support for deterrence theory in the context of extended general deterrence. It also provides evidence that should aid policymakers in designing security structures to meet their goals.In explaining international conflict, most scholars place theories of deterrence in a central position. Theories of deterrence consistently lead to the prediction that deterrent threats that are capable and credible are more likely to be successful. While empirical evidence on direct general deterrence has been generally supportive of deterrence theory, evidence on extended deterrence is less straightforward, mainly because most past research on extended deterrence has been conducted at the immediate deterrence stage. We know

Power changes, alliance credibility, and extended deterrence

“…Just as potential challengers assess the strength and resolve of a potential target before initiating a militarized dispute, they also take into account the capability and credibility of any alliances that state may have. Johnson et al (2015) demonstrate that potential challengers are less likely to initiate disputes against states that are members of relatively strong alliances and alliances where the members share similar foreign policy positions. In other words, potential challengers are able to identify when states are members of capable and/or credible alliances and are wary of getting involved in disputes with them.…”

“…The ratio of the sum of the CINC scores of the potential target and its defensive allies to the sum of the CINC scores of the potential target and its defensive allies plus the CINC scores of the potential challenger and its offensive allies (Johnson et al, 2015) Allies average S-score The average S-score based on alliance portfolios (Signorino and Ritter, 1999) between the potential target and all of its defensive allies (Johnson et al, 2015) Peacetime coordination in target's alliance…”

“…Ordinal measure that codes whether the potential target's defensive alliances require a high, moderate, or low level of peacetime military coordination (Johnson et al, 2015;Leeds and Anac, 2005) Challenger has a relevant offensive alliance Dichotomous variable that codes whether the potential challenger has an offensive alliance that is applicable to militarized conflict with the potential target (Leeds, 2003b;Johnson and Leeds, 2011) Challenger has a relevant neutrality pact Dichotomous variable that codes whether the potential challenger has neutrality pact that is applicable to militarized conflict with the potential target (Leeds, 2003b;Johnson and Leeds, 2011) Natural log of distance The natural log of the capital-to-capital distance between the potential challenger and potential target (Bennett and Stam, 2000) Joint democracy Dichotomous variable that codes whether the potential challenger and potential target both scored a 6 or higher on the Polity2 variable (Marshall et al, 2014) Challenger-target S-score The S-score based on alliance portfolios for the potential challenger and potential target (Signorino and Ritter, 1999) Peace years Codes the number of years since the last militarized dispute between the potential challenger and potential target (Bennett and Stam, 2000) from war is better than its value for the status quo. The potential target's probability of winning a war against the potential challenger is a key component of its expected payoff from war.…”

“…Increases in the second factor can enhance both the credibility and capability of the alliance, also making it less likely for the potential challenger to initiate a militarized interstate dispute. The coding of both of these variables follows the measurement strategy of Johnson et al (2015).…”

Theory, Data, and Deterrence: A Response to Kenwick, Vasquez, and Powers

“…For example, in 1955, Albania goes from having an alliance only with Bulgaria to being part of the Warsaw Pact, including, among others, the USSR. For at least some challengers, an alliance with the Soviet Union and a number of other states might have a stronger deterrence effect than an alliance with Bulgaria (Johnson, Leeds, and Wu 2015).…”