When states form alliances, choosing allies with military strength and similar foreign-policy positions is important for deterring potential challengers, according to new research from political scientists at Rice University and the University of Kentucky. However, in the absence of an ally’s military strength, the similarity of foreign policy positions among allies becomes even more important for deterring threats, and vice versa. In addition, alliances that provide for more peacetime military coordination among member states are more successful at deterrence.
“Capability, Credibility and Extended General Deterrence” appeared in a recent edition of International Interactions. In the paper, the researchers evaluated whether characteristics of potential defenders affect the probability that a potential challenger will initiate a militarized interstate dispute against a potential target.
“Deterrence theory suggests that extended general deterrent threats are likely to be more effective when a potential challenger views them as capable and credible,” said Ashley Leeds, department chair and professor of political science at Rice and the study’s co-author. “We were interested in identifying characteristics of alliances that are most effective at deterrence.”
The researchers found that potential military challengers are 25 percent less likely to initiate disputes when they face a target that has strong military allies as opposed to those with allies of average military strength. Potential challengers are also 31 percent less likely to initiate disputes against states with allies that seem closely linked to them in foreign-policy positions and share a close network of relationships, compared with those with average similarity values.
“When states have closer relations, potential challengers may be more confident that an ally will have incentive to fight on a target’s behalf,” Leeds said. She noted that these results are consistent even in situations when the potential target is relatively weak compared with the potential challenger.
The study also found that in the absence of an ally’s military strength, it is more important for an ally to have similar foreign-policy positions to successfully deter threats. Conversely, when a state does not share its ally’s viewpoints on foreign policy, it becomes more important for the ally to be militarily strong. Finally, the results suggest that provisions in alliances that promote peacetime military coordination improve the ability of the alliance to deter threats. A state with an alliance with a high level of military coordination is 23 percent less likely to be the target of a militarized dispute than a state that has an alliance that requires a low level of military coordination.
The study analyzed data on dispute initiation and military alliances from 1816 to 2000. The data came from the Correlates of War project and the Alliance Treaty Obligations and Provisions project.
Leeds and her co-authors hope the study will encourage further studies of alliance choices and peacetime military coordination within alliances.
“So many of the factors that affect the probability of military conflict are outside the control of policymakers,” Leeds said. “Choosing allies and designing the means by which allies coordinate policy is something policymakers can control, and thus research on the effectiveness of different kinds of alliances at promoting peace is important.”
Source: Rice University