Troop presence in Vietnam surged from a few thousand in 1963 to half a million by the time LBJ was done wrecking both the country and the situation, and then Nixon expanded it all outward, jumpstarting the monster that has become the "military budget," our military presence around the world, and our interventionist stance, along with the many, many enemies we have created.
Much of that dates back to WW2 and its immediate aftermath, actually. In terms of all the over seas bases and stuff as part of the long-term Cold War military aparatus. Interventionism became firmly established in World War II and we were meddling in foreign countries, trying to leverage favorable gov't structures, as far back as Iran and Morocco in the early 1950's.
The Italian general election of 1948 was before the 1950s, I think.
