Pavel Podvig has a fabulous article in the Summer 2008 IS on the development of Soviet nuclear doctrine and force structure in the 1970s:
The data presented here demonstrate that concerns about the U.S. “window of vulnerability,” which figured so prominently in U.S. political discussions of the Soviet Union’s missile modernization program in the late 1970s and early 1980s, were unjustified. Contrary to the perception that existed at the time, the program did not have the potential to pose a serious threat to U.S. strategic forces. The evidence also strongly suggests that the Soviet Union had neither a plan nor the capability to fight and win a nuclear war.
The upshot is that there’s no indication that the Soviet consciously sought a first strike capability against the United States, or at any point structured their force around that eventuality. Rather, Soviet aims were predominantly defensive, oriented around the threat that US missile capabilities presented. Of course, as Podvig notes:
This is not to say that the Soviet military programs were benign or that the Soviet Union did not strive for military or political advantage, or at least parity with the United States. As documentary evidence of the Soviet programs continues to emerge, however, it is becoming increasingly clear that the Soviet military buildup was driven primarily by the inertia of the military industrial complex and by a lack of mechanisms to contain the country’s military programs.
The most notable implication of this study is confirmation that the “Team B” exercise of the 1970s, commissioned in substantial part by George H.W. Bush, was an unmitigated disaster. It was wrong in pretty much every way that intelligence analysis can be wrong, and it should stand as a lasting black mark on the reputations of its participants and adherents. While we can never fully demonstrate whether Team B was engaged in pure fantasy or intentional deception, I’m guessing predominately column B. Never a bad time to revisit this hilarious little piece of propaganda: