It is true that nations sometimes choose to go to war to prevent a rival from acquiring military capabilities that could pose a grave offensive threat over time. This dynamic fueled Israel’s decision in 1981, and Washington’s in 2003, to attack Iraq over its suspected development of nuclear weapons. But this is a less credible casus belli in cases where the aggressor already enjoys an overwhelming military advantage and faces little prospect of being threatened offensively by the country in question.
