There are obvious differences between welfare and war. But the principle of self-reliance extends far beyond welfare. It suffuses the entire Republican platform, from taxes to federalism to job creation. It’s a fact of human nature. It’s why you try that much harder to find a job when the government cuts off your benefit check. It’s why you have to fix your army and your government when U.S. troops aren’t there to take the shrapnel for you.

Republicans say ISIS is filling the “vacuum” left by Obama’s withdrawal. But the vacuum—which is really just another name for how the world works when we’re not there—affects other parties, too. As ISIS advances on Baghdad, Shiite militias are assembling. Iran is stepping in. Turkey may be next. The conflict could explode into sectarian civil war, though some Shiite leaders are trying to avoid that. But what’s striking is how quickly, in our absence, the threatened elements of Iraqi society and the region are mobilizing to stop ISIS. They’re doing it because they have to. If they don’t, nobody else will.