I have heard that the brinkmanship foreign policy of Eisenhower and Kennedy lead, in part, to the Cuban Missile Crisis. However, I am curious: did the Truman Doctrine also contribute, in part, to the Cuban Missile Crisis?
It is unfair, in my opinion, to qualify all resistance to Soviet expansion post WW2 as brinkmanship. Truman managed, quite well, the response to an unprovoked attack in Korea and was confronted with a powerful block of nations subjugated by the USSR with a fundamentally inimical drive to impose their ideology on the world. Led, until 1953, by which time Truman was gone, by Stalin, who was a homicidal paranoid.
The Truman Doctrine, coming soon after WW2, was basically saying "we will not sit idly by as the world did in 1933". It is a fairly measured stance, although the USSR was, on occasions, reminded that US nukes were on standby, should it not do as the US wanted. Yes, there were abuses in anti Communist hysteria, such as McCarthy, but that does not make resistance against a political system which spawned the Gulags and the 1932 Ukraine famine unjustified.
If brinkmanship there was, it was all Kennedy's. He got elected in 1960 by campaigning on a missile gap at the US's detriment. But he was also on the Senate Defence Committee so he knew perfectly well that, while there was a missile gap, it was all the other way, which is why he strongly suspected they would blink during the crisis. The US had stationed missiles in Italy and Turkey - long range nukes which were not so much a defence for the country hosting them as a threat to Russia itself.
Bay of Pigs. Involvement in Vietnam. Cuban Missile Crisis. These are all Kennedy's. The Truman Doctrine provided a reasoned and thoughtful framework to counteract the Soviet threat, but was just a formalization of US intents. Kennedy went all in on his own judgment, mostly with fairly negative results. Later on, to little benefit, US fighting capacity would be getting bled out in Vietnam while US forces in Western Europe were understrength, all without a single Russian being at risk.
Contrast Kennedy in a way with Reagan, who also got elected on a tough-on-Communism approach. But was smart enough to grasp the opportunity Gorbachev's reform was offering and avoid direct US military adventures (although it must be said, the stain of the Central American CIA-supported death squads is largely on his watch).
No, Kennedy's reckless adventures are his own and the Truman Doctrine is not to be blamed for it. The intent was good, to resist Communism. The ways he went about it were unnecessarily risky and I am always surprised by how popular he remains. More to do with his looks and his assassination than his achievements, in my opinion. Even his handling of the Civil Rights movement is nothing to brag about.
To start, I think it's safe to say that regardless of doctrine, the USA was not going to tolerate nuclear weapons on its doorstep.
While it's clear that the USA was staunchly anti-communist, the Truman Doctrine also had a focus on providing aid to countries fighting the threat of Communism. By this point Cuba was already Communist, and the Bay of Pigs Invasion was an attempted overthrow of the Communist government.
Indirectly, with this doctrine of providing aid to other countries, American nukes were placed in Turkey and Italy (NATO members), which scared and angered the Russians, and prompted the installation of nukes in Cuba.
In summary, as with many events during the Cold War, the causes are not always singular and categorical, and there may be multiple reasons and their interactions for what eventually transpires.