For starters, the 2-percent figure is arbitrary. It doesn’t measure how much a country actually contributes to the common defense. As The Washington Post has noted, Greece meets the 2-percent threshold because it spends a lot of money on military pensions and on weapons systems aimed at deterring its fellow NATO member, Turkey—neither of which makes America and Europe safer. Rachel Rizzo, an expert on trans-Atlantic security at the Center for New American Security, told me Germany could reach the 2-percent threshold by giving everyone in its Ministry of Defense a raise. That wouldn’t do much to enhance security either.

But the larger problem with demanding that America’s NATO partners spend 2 percent—or 4 percent—on defense is that it assumes Europe’s biggest threats are military. The 2-percent figure dates from 2014, when the Obama administration pushed through a statement pledging that NATO members “aim to move towards the 2% guideline within a decade.” Back then, Russia had just annexed Crimea. And when asked why NATO countries should spend 2 percent, experts often cite the fear that Russia—having invaded Ukraine—might invade NATO countries like Estonia, Lithuania, and Latvia.

But that’s extremely unlikely. In his almost 20 years in power, Vladimir Putin has intervened militarily in Ukraine and Georgia, countries that are not NATO members, likely in part because he knew doing so would not risk war with the United States and its major allies. But since NATO members are bound to defend one another, invading Estonia, Lithuania, and Latvia—which host troops from Britain, France, Germany, and Canada on their soil—would risk exactly that. When Putin contemplates such a conflict, he’s surely aware that NATO spends more than 13 times as much as Russia on defense. Even if you didn’t count U.S. spending, the other members combined spend more than four times as much as Russia. And that’s without most of them reaching the 2 percent of GDP goal.

The threat of Russia actually invading the Baltic states is very small. And Russia poses basically zero military threat to larger NATO members like France, Germany, Italy, and Spain. The far larger threat to Europe is ideological. It’s rising authoritarianism. Poland is on track to meet the 2-percent threshold even as it eviscerates the independence of its Supreme Court. Russia exacerbates that ideological threat by supporting illiberal political parties, but the real driver of European authoritarian impulses is mass migration. In recent years, war, state collapse, and climate change have sent millions streaming toward Europe from North Africa, sub-Saharan Africa, and the greater Middle East. And Europe’s failure to effectively handle these flows has sparked a hyper-nationalist response that in many countries threatens liberal democracy.