Today, January 27th, marks 50 years since the signing of the Paris Peace Accords which effectively ended American participation in the Vietnam war. One of the consequences, according to Georgetown University international affairs scholar Charles Kupchan, was that an “isolationist impulse” made a “significant comeback in response to the Vietnam War, which severely strained the liberal internationalist consensus.” As the Cold War historian John Lamberton Harper points out, President Jimmy Carter’s hawkish Polish-born national security adviser, Zbigniew Brzezinski, scorned his...