Libertarian perspectives on foreign intervention
Libertarian perspectives on foreign intervention started as a reaction to the Cold War mentality of military interventionism promoted by American conservatives, including William F. Buckley Jr., who supplanted Old Right non-interventionism. The Vietnam War split the uneasy alliance between growing numbers of self-identified libertarians and the Cold War conservatives.
Source: Wikipedia — Libertarian perspectives on foreign intervention (CC BY-SA 4.0)