The tables are turning on Moscow. Putin for a few years intimidated the West. He took Crimea by force, fomented and fed a separatist war in Ukraine’s southeastern Donbas region, and moved decisively into the Syria wars when former U.S. President Barack Obama stood back.

Russia still has Crimea but is stalemated in the Donbas, and economic sanctions imposed for these and other aggressive policies are working. In Syria, the Iranians have military and political influence at least on a par with Moscow.

The result of Putin’s gambles is what strategic theory predicts. An aggressive great power either intimidates smaller powers or provokes a coalition against it. The same is happening in Asia, where China is provoking a coalition of Japan, South Korea, and Vietnam. In both cases, however, it is the United States that anchors the smaller country alliances. American leadership in the form of geostrategic guarantees against China and Russia is in the American national interest.