Peaceful Uncertainty: When Power Shocks Do Not Create Commitment Problems

Does a shock to the balance of power cause the advantaged actor to exploit its newfound advantage by initiating conflict? The modeling literature on commitment problems as a source of war makes a central assumption that states know and anticipate power shifts. We relax this assumption such that states must estimate future power shifts by looking at past and present capabilities—both their own and those of their adversaries. We incorporate these estimates, and their attendant uncertainty, into a model of war. We find that commitment problems remain a source of war, but that the existing models overpredict war by ignoring this dynamic. States continuously updating their estimates and accounting for uncertainty promotes peace. It follows that the apparent window of opportunity—in which the power balance becomes suddenly favorable to one side—poses less of a threat to peace than previous theories suggest. This result has applications to nuclear proliferation dynamics and conflict in general. We find empirical support for the model in tests analyzing power shifts and interstate wars.

权力均势（balance of power）的冲击是否会促使优势行为体利用其新获得的优势挑起冲突？以承诺问题（commitment problems）作为战争成因的建模研究文献，有一项核心假设：国家能够知晓并预判权力转移。我们放宽了这一假设，设定国家必须通过审视自身及对手过往与当前的实力，来估算未来的权力转移，并将这些估算及其伴随的不确定性纳入战争模型之中。研究发现，承诺问题依然是战争的成因之一，但现有模型因忽略这一动态过程而高估了战争爆发的概率。国家持续更新自身的实力估算并考量不确定性，这一行为有助于维护和平。由此可见，看似存在的机会之窗——即权力均势突然向一方倾斜的时段——对和平构成的威胁，要小于此前理论所预判的程度。这一结论可应用于核扩散动态及一般性冲突研究。我们在针对权力转移与国家间战争的实证检验中，为该模型找到了支撑依据。