Pushing and pulling: The Western system, nuclear weapons and Soviet change

The security environment of the Soviet state during the Gorbachev period was distinctly different from earlier periods. The increased number of non-aggressive states in the Soviet Union's international environment further enhanced the security of the regime in historically unprecedented ways. Nuclear weapons freed the Soviet Union from fears of territorial aggression, while making its own expansion too costly. The achievement of military parity with the West gave the Soviets a further enhanced sense of security. Nuclear weapons also created significant common threats from nuclear war, providing strong incentives for accommodation and cooperation. Looking from the post-Cold War era, both Reagan and Gorbachev finally turned out to be anomalies. The particular circumstances that had created the opportunities for extraordinary breakthroughs by the diplomacy of these two men disappeared almost as quickly as they had arisen.