Turkey has tried its best to stay out of the Iran war, studiously maintaining its neutrality. In this effort, it can point to precedent from its own history. Generations of Turkish policymakers cite the high-stakes balancing act Ankara performed during World War II as one of the golden chapters of Turkish diplomacy. At the time, Turkey’s leaders were acutely aware of the young republic’s geopolitical isolation and military vulnerability—and determined not to repeat the error of their Ottoman predecessors, who picked the wrong side in the previous world war, bringing about the collapse of the empire. As war raged at its borders, Turkey negotiated with both the Allies and Germany, and its ultimate achievement was preserving its neutrality despite the pressure of surrounding belligerents. The war in Iran has required a similar calculation. Unlike in the 1930s and 1940s, Turkey today has sought a larger role on the world stage.…