[identity profile] harimad.livejournal.com 2014-10-17 02:43 pm (UTC)(link)
Even before the Soviet invasion of Afghanistan, Carter was becoming a soured idealist about US-SU relations. The invasion, of course, pounded the final two dozen nails in that coffin. But if you look at defense budgets under Carter and Reagan (and remember that the 1981 budget was Carter's, not Reagans) you can see that evolution.

Also, before Star Wars Reagan was making noises about moving more and bigger nukes into Europe. At the same time was NATO exercise ABLE ARCHER, which simulated a nuclear war in Europe; the Soviet Union was the unnamed opponent, of course. The Soviet Union thought that Reagan/NATO was using ABLE ARCHER as a ruse for a nuclear first strike ... and therefore started making preparations to participate in a nuclear war.

It was a close-run thing.

[identity profile] david wilford (from livejournal.com) 2014-10-17 03:49 pm (UTC)(link)
The 1970s were scary as the logic of MAD played itself out with the Soviets deploying new missiles that gave them the capability of launching a first strike on U.S. missile silos while still maintaining a reserve that could be launched at U.S. cities. So the U.S. was developing newer missiles like the MX to counter Soviet moves, and so on.