Ouch! Cuban Revolution 1959: Castro came to power. Eisenhower's watch.
Actually, Truman was responsible (with Dean Acheson, his Secretary of State,) for the poicy of Containment, aiding the Greek government against a communist takeover immediately after WWII. He was an anti-Communist who was stuck with the deals that FDR had made with Stalin regarding Eastern Europe after WWII.But he did come up with the pre-eminent policy of the Cold War, which was to contain Communist expansionism
Of course this meant fighting them in the Korean peninsula, and later, in Vietnam, as well as in various proxy wars fought by us and our allies in Malaysia, Indonesia, Central America, Southern Africa, and so forth.
Containment was a terribly risky and ineffective policy. Rather than nip the global communist revolution in the bud we chose to play defense. This cost a hundred million more lives that would have been lost crushing Stalin at the outset. We also spent forty years with the threat of nuclear annihilation looming.
Containment allowed the USSR to pick off their targets, and steadily increase the number of satellite, communist, or sympathetic nations. The concept of rollback was abandoned early on, so once a country became communist, it stayed communist.
The wars we fought during containment were uniformly disasterous, because they weren't supposed to win. The best Vietnam or Korea could have ended with was a tie, because that outcome had been required by Washington. Containment wasn't about retaking lost ground, only holding onto what you had. This forces a 'win-lose' mentality where 'win' really means 'tie'.
It wasn't until Reagan, who's policies were a dramatic break from simple containment, that we were able to force the hand of the Soviet Union. Rather than try and maintain the status quo, he called them the 'evil empire' and aggressivly built up our military to bring pressure on them.
Containment is the philosophy of 'Don't hit me, or I'll try and block you', as opposed to 'Don't hit me, or I may hit back'. It failed us for decades, in a long and well documented fashion.