European nationalist conflicts will rise in America’s absence

For seven decades, American power has been the invisible architecture holding Europe together. More than just its security guarantee under NATO, the U.S. military presence checked historic rivalries, subsidized collective defense, and created the conditions for unprecedented peace and prosperity.

During the Cold War, that guarantee meant Europeans could focus on cooperation among themselves and with America rather than on nationalist conflagrations. And the U.S. guarantee largely survived the end of the Cold War. Western European powers such as Belgium, Germany, Italy, and Spain took full advantage, devoting barely 1% of their GDPs to defense while investing in generous social programs.

The Trump administration is changing these dynamics. Its recent push to take Greenland from its NATO ally, Denmark, has heightened European anxieties and calls for