the threat of Massive Retaliation could not prevent limited challenges. It was not an effective foreign policy tool to deal with everyday problems. Short of an ultimate provocation, the Soviet Union could raise tensions and challenge the U.S. as the Korean War already had shown and future crises involving Berlin would again prove. In other words, more limited responses were necessary to deal with less-than-total challenges.
The Soviet Union successfully tested American resolve several times. On 17 June 1953 it suppressed an anti-Communist revolt in East Berlin and in late 1956 it suppressed a national uprising in Hungary.
What were the mistakes of Massive Retaliation? First, Massive Retaliation lowered U.S. credibility. It was not credible to threaten the Soviet Union with massive retaliation in the face of its growing strategic power. Even if U.S. politicians really meant it, people in other capitals would not believe it. If the threat was losing credibility in the eyes of the very nation it was supposed to deter, then the policy had lost its meaning.
Second, Massive Retaliation increased the vulnerability of the opponent. As a consequence the U.S. Strategic Air Command (SAC) was becoming more vulnerable to a surprise attack. If the Soviet Union felt insecure because of Massive Retaliation, Moscow might decide to strike first. Growing vulnerability could be strong incentive for such a first, disarming strike.
Why was Massive Retaliation so attractive? Massive Retaliation was attractive because it was containment "on the cheap." It also was an attempt to explain the Korean War. Korea would never have happened, the argument went, had the Communists known that the US would retaliate. So, when allies feared a lack of American commitment to extended deterrence it could be explained or, at least, it could be declared away with excuses: We had a communication problem; the other side did not know that we were deadly serious.
Was Massive Retaliation at all credible? Massive Retaliation was only plausible as long as Soviet Union could not retaliate. In other words it was based on the assumption of U.S. territorial invulnerability. During the Cuban Missile Crisis this assumption was challenged. The Soviet Union wanted to make the United States territorially vulnerable to the extent that it itself was territorially vulnerable to Western delivery systems in Europe. However, the Soviet Union launched its first Inter-continental Ballistic Missile (ICBM) in 1957. That means that long before the Cuba crisis and at the time that Massive Retaliation was announced, the military strategy was questioned by the people who designed it.
Soviet ICBMs threatened the territorial invulnerability of the United States, and the question came up whether the U.S. would risk nuclear suicide for the sake of its allies. The U.S. willingness to sacrifice New York for Berlin, seemed implausible. Thus Soviet ICBMs diminished the credibility of extended nuclear deterrence. For U.S. allies the specter was raised that U.S. military strategy might move from a deterrence posture to a defense posture. This change in strategy, however, implied the consideration of Europe as a future nuclear battle field and consequently endangered alliance management.
From Massive Retaliation to Flexible Response
A nuclear power in charge of an alliance has to deter the opponent and to reassure the allies. The alternative to reassuring U.S. allies would have been for Europeans to produce nuclear weapons themselves and create core deterrence themselves either on a national basis or in cooperation with other Europeans. It also would have meant that the Germans would have gotten a finger on the nuclear button
From the perspective of the United States, nuclear parity and territorial vulnerability
required the adoption of a new strategy. The Kennedy administration accepted a new strategy, called Flexible Response .