asked the Secretary of State for Defence from international sources available to him, what has been the increase in numbers of strategic nuclear missiles deployed (a) by the United States of America and (b) by the Union of Soviet Socialist Republics since 1967.

Taking the figures published by the International Institute of Strategic Studies, the United States strategic missile force has remained constant in number over the period—at 1,710 —whereas the Soviet Union's ICBM and SLBM force has increased from around 600 to 2,400 systems. But taking into account all factors in the strategic equation—including air-launched systems and the number of independently targetted warheads per missile—there is a broad parity between the two Powers.