If you haven't, I'm going to recommend you to listen to an episode of Dan Carlin's Hardcore History, specifically The Destroyer of Worlds [1].

Why? Because it goes into the change in strategic thinking brought on by the atomic age (and, soon thereafter, the thermonuclear age). And there was an element of US strategic thinking that argued for a preemptive strike against the USSR.

The episode also goes into the arguments for and against the development of the hydrogen bomb, a weapon that could never really be used and arguably not even necessary when we already had the atomic bomb.

The outcome of those debates shaped American foreign policy from 1945 to the present day.

[1]:https://www.dancarlin.com/hardcore-history-59-the-destroyer-...

  With the Russians it is not a question of whether but of when. If you say why not bomb them tomorrow, I say why not today? If you say today at 5 o'clock, I say why not one o'clock?  -- John von Neumann, ~1950