US foreign policy in five doctrines

Looking back at five big US foreign policy shifts from the Monroe doctrine in the 19th Century to the post-9/11 strategies of the Bush doctrine in the early 2000s. Justin Webb and his guests examine how America’s approach to the world has constantly changed over time, to help answer a really big question - how radical is the way President Donald Trump deals with the world? Is he really an outlier in US history? Or do his actions reflect the changing patterns of American power?