Events, not warhawks sidelined Kennan. Stalin's ill-conceived blockade of Berlin, the Berlin airlift, the Communist coup in Czechoslovakia, Soviet-backed insurgencies in Greece and Turkey had more to do with jump starting the cold war than American warhawks. Stalin was terrified of a successful Marshall Plan and American-led Franco-German reconciliation.

My parents got married on June 25, 1950, the day North Korea invaded South Korea. Who were the militaristic warhawks there? Truman firing the megalomaniacal narcissist MacArthur showed that the warhawks were better contained on the American than the Soviet side, at least until Stalin's dead in March 1953 that allowed for armistice in Korea in July. The depersonalization of the Soviet regime--a transition from rule by neo-czarist Stalin cult to totalitarianism by committee--then led to revolt in East Germany in 1953, in Hungary in 1956, Khrushchev's "secret" speech denouncing Stalin's crimes, the 1968 Prague Spring, labor revolt in Poland in 1970 and 1980. I was in Hungary and Yugoslavia in the summer of 1980 and saw firsthand how brittle these rickety mafia with a flag one party states were. Communism made sense only if you lived in early 70s fascist Spain and Portugal ("contra Franco luchabamos mejor"). Even Italian and Spanish Communist Party leaders Berlinguer and Santiago Carrillo understood this.

So I'd argue that American militarism didn't produce the cold war, but that the end of history unipolar hubris generated by the lack of a cold war rival made the militarism Eisenhower warned us about worse.

But there are unintended benefits to the American national security state. Imagine how much more unchecked Trump's power would have been without it. Had you told me in the 70s and 80s that there would be a right wing populist Russian asset in the White House and the American left was supporting the FBI and the CIA, I'd have asked what are you smoking, and can I have some.