In 1963 Macmillan again played a key role in setting up a new round of talks in Moscow. Nikita Khrushchev was adamant there would be no onsite inspections but did put forward two proposals for a partial test ban and an East-West non-aggression pact. During the talk Soviet negotiators seemed on the verge of withdrawing. The Americans were unwilling to discuss a non-aggression pact because it involved other allies. The British representative, Lord Hailsham, suggested that the treaty include a clause stating the desirability of a non-aggression pact. A partial test ban treaty banning the testing of nuclear weapons in the atmosphere was signed in August 1963.
Having the status of a nuclear power during the 1960s, the British government was committed to the non-proliferation of nuclear weapons. Britain's aim was to protect its position against non-nuclear powers and maintain the existing nuclear balance.
For the British government a non-proliferation treaty was also a means of overcoming the American Multilateral Force (MLF) initiative. Following the abandonment of MLF in 1966, the US dropped the idea of nuclear sharing and accepted the idea of non-proliferation.
During Alexey Kosygin's visit to London in 1967 the British played an essential role in persuading non-nuclear powers in the Eighteen-Nation Disarmament Conference (particularly West Germany and the Soviet Union) to support non-proliferation. A Nuclear Non-Proliferation Treaty was opened for signature in July 1968 and came into force in 1970. Britain's subsequent interest in the Strategic Arms Limitation Talks was less significant, and the government did not play a major role.