Wikipedia suggests that aggressive Western acts in the early 1980s, culminating in the Able Archer exercises in 1983 convinced some members of Soviet high command that a genuine nuclear first strike was imminent and could easily have provoked a war. I'm curious if this is legit history or a classic Wikipedia foregrounding of a marginal theory.
It's legit but you have it a little mixed up. Soviet high command was already paranoid about a first strike (see Project RYaN, which is a reflection and cause of that — chasing noise, looking for signs of preparation), and Able Archer was, to a paranoid mindset, a perfect way to implement that ("hey, we'll fake an attack on you guys, but will totally NOT follow through with it..."). The Soviets went into a relatively high alert mode, and had something gotten confused/mistaken/bad signals/off course/whatever, it could have been bad. (Imagine if the Stanislav Petrov incident had happened in the middle of it, instead of a month or so earlier.) This is what makes it similar in character to the Cuban Missile Crisis — lots of plates in the air, so to speak, during a very tense period means there is less leeway for misunderstandings or accidents (and there is some underlying rate of misunderstandings and accidents anyway).
Anyway, David Hoffman's The Dead Hand has a bit on Able Archer (and the other crazy things that happened in late 1983, like Stanislav Petrov and the KAL 007 shootdown), but the Electronic Briefing Books by the National Security Archive contain great analysis and raw documents that have been declassified on this, some quite recently. This set in particular is worth looking at. I see from the page that Nate Jones published a book just last month on this — I haven't read it yet but it looks interesting, and the National Security Archive staff are real pros at this kind of thing.