For decades, America has pursed a foreign policy of liberal hegemony: the idea that the U.S. should use its power to spread values like freedom and democracy, often by using military force.  America's foreign policy elite, whether in government, think tanks, media, or academia, have largely supported this strategy.  But Harvard University's Stephen Walt thinks America's expansive global reach has harmed our national security--and our elites have not been held accountable for their preferred foreign policy's devastating failures.