When a great power takes a gamble, the world shakes. By ordering an attack on Ukraine, Russian President Vladimir Putin has unleashed a chain of reactions whose endpoint no one can yet foresee. Already apparent, however, is one consequence for the United States. Overstretched to begin with, America has just seen its strategic burden increase. Just as suddenly, however, a new solution is coming into view: Europe is ready to take on greater military duties.

Before the war, many Americans, including some political leaders, had determined to be more realistic about their country’s strategic ambitions in an increasingly competitive world. Sensibly, President Biden had sought to stabilize relations with Russia and reduce U.S. war-making in the greater Middle East while turning attention and resources toward managing a rising China. But Putin’s Russia has refused to be sidelined. By invading Ukraine, it has caused NATO’s eastern flank, with four countries bordering Russian territory, to demand reinforcements — and the United States has risen to the task. Biden has sent 14,000 American troops to Europe since the crisis began, bringing the total to 100,000.

Providing temporary reinforcements is the right decision today in the face of Russia’s bald aggression. But the United States should resist the inclination to revive its role as the military protector of Europe, especially since Europe is awakening to its responsibilities. Britain is sending troops to the Baltic states and Poland. France is pushing “strategic autonomy” for the European Union. And days after halting the Nord Stream 2 pipeline supplying natural gas from Russia, Germany reversed a long-standing ban on providing military assistance and sent weapons to Ukraine. Germany also vowed to spend more than 2 percent of its economy on defense, finally committing to meet NATO’s target. German Chancellor Olaf Scholz declared his country, and Europe, to have reached a “historic turning point.”

Both Americans and Europeans would benefit if Scholz’s words prove true. In the coming years, European states should move to take the lead in their collective defense, and the United States should do everything possible to encourage them. To stake the defense of Europe on the United States, over the next decade and beyond, would be to answer Putin’s rash gamble with a slow-moving gamble of our own.