> That arms race is the only reason why we haven't had a major war in the last 75 years, and won't have one in the foreseeable future.

The Cold War was one of largest wars in history by casualties, on the same rough order as (and possibly ahead of) WWI.

Nuclear weapons are a big part of why it was popular to maintain the rather paper-thin fiction that it was simply a series of separate conflicts that happened to have the same parties standing behind the principal combatants (or involving at most one of those backers directly).