The leaders of both 'super powers' - Leonid Brezhnev (Russia), Lyndon Johnson and later Richard Nixon (USA) had financial reasons for wanting to reduce defence spending. Brezhnev felt that the economic burden was unsustainable and the Vietnam War had drained the American economy and Johnson needed to expand the American welfare state. This coupled with the realisation that each side had the capability of mutually assured destruction led to a growing awareness of the need for dialogue.

The policy of the West German leader Willy Brant - Ostpolitik - was helping to decrease tension in Europe. The Soviet Union hoped that this would lead to greater trade opportunities with the West and thought that perhaps a less aggressive policy towards Western Europe may encourage them to detach themselves from their American ally.

The Sino - Soviet split caused concern within the Soviet Union. It was felt that this rift would encourage the Chinese to look to Americas as an ally and so create a Sino - American alliance that would work against them. The Americans were keen to foster a relationship with the Chinese as this was viewed as a way to drive apart two of America's enemies.

The three great powers - United States, Russia and China each had their own motives for being a part of this détente. Pressures at home and abroad encouraged the three leaders to look for ways of co-operate with each other whilst at the same time maintain their political views.

Throughout the seventies, the American government fostered relationships with China and opened a dialogue with Russia that led to the signing of SALT 1; SALT 2 and the Helsinki Accords. By the end of the seventies this détente was over for several reasons. The most fundamental of these was each side's interpretation of the definition and purpose of détente.

The Soviets were prepared to come to an agreement on arms control as a reduction in arms spending would have economic and social benefits for the Soviet leadership. The other aspects of détente - human rights and trade issues - were of minor consequence to them and only acceptable if they were of benefit to Russia.

The Americans and her Western allies became increasingly concerned that despite all the agreements Russia was still increasing her military forces. As a consequence America increased her spending on arms and stationed intercontinental ballistic missiles in Europe, a move that angered the Soviets.

During the 1980's the situation worsened with Western leaders referring to Russia as the 'evil empire'. The Soviet invasion of Afghanistan (1979) and her attitude towards dissidents served to support this view. However, the whole arms race became destabilised when President Reagan (USA) announced the 'Strategic Defence Initiative' or 'Star Wars' project. The creation of this defensive shield would make Russia more vulnerable to attack from America with the shield making retaliation difficult. Other incidents such as the shooting down of the Korean airliner KAL 007 (September 1983) ensured that détente was not considered as a relevant topic. It was not until the fall of the Berlin Wall in 1989 that the dialogue between East and West was fully reopened.