This video featuring Reason’s Brian Doherty on “the forgotten history of the antiwar right” is worth watching.
Doherty, author of Radicals for Capitalism: A Freewheeling History of the Modern American Libertarian Movement, makes some interesting points, including noting that World War I (and I would implicitly add a rejection of Wilsonian idealism) made antiwar libertarianism a respectable position during the 1920s and 30s.
And he correctly noted that conservatives such as William F. Buckley “took the view…that the threat of Soviet Communism was so severe that for the duration of the Cold War…we had to give the government all the power it needed…”
Lastly, I think Doherty is correct in his observation that the high-profile nature of young Americans protesting the Vietnam War in the streets gave the incorrect impression that being antiwar was solely a leftist cause.
Where I think the video is lacking — and this may be the product of editing — is its failure to note what might be the single greatest reason the antiwar right essentially disappeared: World War II.
To be sure, the Communist menace played a major role in justifying continued military intervention from the 1960s onward, but I would argue it was World War II that discredited isolationism and “neutrality” as modern foreign policy alternatives (not to mention making an antiwar stance politically untenable for any major party or ideology to embrace).