There were a few types who were tilted towards preemptive or preventative war. The scientist John von Neumann, who served in various high level committees and government posts, was fond, in the early 1950s of asking people whether they thought nuclear war with the Soviet Union was likely to occur (most people did), and then asking, "so why not today?" The US had a huge advantage in terms of weapons and their deliverability until the 1960s, and even in the 1960s the USSR's ability to attack the continental USA was still relatively limited. (By the 1970s, the USSR was at true nuclear parity.)

During the Cuban Missile Crisis, the Secretary of the Air Force, Curtis LeMay, also argued that the US ought to just strike first. This is less the Jack T. Ripper approach than the Buck Turgidson approach — if you were already getting into it, you might as well go full-steam ahead and take advantage of the situation, even if you would get your hair a little "mussed."

It is worth noting that Kennedy was disturbed enough about the possibility of rogue generals (the Gen. Ripper problem) possibly using nuclear weapons that he began the process of forcing all nuclear weapons (initially just those deployed abroad, but eventually domestic ones as well) to have sophisticated, code-based locking mechanisms on them to prevent unauthorized use. This is a very different approach from Eisenhower's "pre-delegation" policy whereby some military forces were pre-authorized to use nuclear weapons if they felt the situation required it (and had the means to do so).

In the early 1950s, the idea of a pre-emptive strike against the USSR was fairly common in American policy-wonk and even some military circles, along the reasoning above ("we have an advantage"/"costs would exist but we would survive"/"if it's going to happen, it might as well happen now before it is truly existential to us"). It was for rather obvious reasons not popular in Europe (which would bear the brunt of any Soviet nuclear retaliation, and would be exposed to fallout from an American attack on the Soviet bloc), and it was not popular amongst the American general public (Gallup polls on preemption never put it more than 15% or so of the population, which makes it a very fringe position indeed — my rule of thumb is that you can get 10% of the American public to agree to pretty much anything in a poll, no matter how silly or stupid).