Not really a good example, honestly. Kennedy’s involvement in Vietnam was the culmination of the previous two decades of events (Korean War, Cuban Missile Crisi

Not really a good example, honestly. Kennedy’s involvement in Vietnam was the culmination of the previous two decades of events (Korean War, Cuban Missile Crisis, Taiwan standoff, etc.), and not just a crusade he charismatically fooled everyone into joining. If anything, had Nixon won in 1960 (and defeated Kennedy), it’s possible that the war would have escalated more quickly.