We have had two consecutive presidents - Barack Obama and Donald Trump - who have in their own way recognized the limits of American military power in achieving political outcomes across the globe, yet we have been at war the whole time they've been in office. They were preceded by a president who promised a humble foreign policy," no nation-building, and military involvement only where the exits were clearly marked. But George W. Bush's abandonment of those campaign planks set the United States on a foreign-policy course that has clearly not worked as planned. Still, at least he was operating in the immediate aftermath of the 9/11 terrorist attacks, before all the unintended consequences of Iraq-style regime change were so blatantly known. Neither Obama nor Trump has that excuse. Obama largely owes his presidency to his 2002 speech opposing the invasion of Iraq and other "dumb wars." Trump won the 2016 South Carolina primary the day after denouncing the Iraq war in terms that got Ron Paul nearly tossed off the debate stage in the same state a decade ago. The foreign policy advice presidents receive is predominantly hawkish. So is the reinforcement they get from the Washington establishment. Things happen all over the world that seem to cry out for some kind of American response. But ... until some of this institutional bias in favor of intervention changes, we will keep voting for presidents who promise peace but deliver war.