LONDON — BOWING to United States pressure, Britain has decided to reduce by at least a quarter the firepower of its nuclear deterrent, and in the future will actively support calls for a comprehensive treaty banning nuclear tests.
In what defense analysts see as the beginning of a reshaping of the nation's strategic policy, Defense Secretary Malcolm Rifkind also proposed on Nov. 16 closer cooperation with France on nuclear matters.
The ending of the cold war put Britain's nuclear planners in a dilemma. Before the collapse of communism, the government ordered four Trident submarines, at a cost of 10 billion ($1.5 billion), to replace its aging Polaris fleet.
The new deterrent would have massively increased Britain's nuclear firepower at a time when the US and Russia were reducing theirs. Each Trident boat is capable of carrying 128 warheads.
Mr. Rifkind has set a ceiling of 96 warheads per submarine, and has indicated that when the boats go to sea they may carry significantly fewer than that.
Britain has already ordered cuts in sub-strategic nuclear systems such as the Lance missile and maritime depth bombs. In October Britain abandoned plans to develop a new air-launched missile for Royal Air Force strike planes.
Until now Britain has supported the principle of a test ban, but has been allowed to test its nuclear warheads in the US.
The Clinton administration, defense sources say, has told Britain that testing is not consistent with a commitment to nuclear nonproliferation and has been pressing Britain to adopt a test-ban stance.
RIFKIND said the policy shift had ``not been an entirely easy decision'' because nuclear testing had ``played a central role in maintaining the highest levels of nuclear safety assurance.''
In the future Britain would have to ``work hard'' to ensure that those levels were maintained ``without testing.''
The defense secretary said Britain would ``press hard'' with the US for an indefinite extension of the Nuclear Non-Proliferation Treaty in 1995. He added, however, that Britain would continue to affirm the right of first use of nuclear weapons in a crisis.
``A no-first-use declaration would take us out of the realm of war prevention,'' he said.
Unlike other defense cuts now being made, Britain's decision to curb nuclear weapons is not being driven by the need for government economies. Most of the money for the Trident fleet has already been spent or committed.
There is likely to be controversy over Rifkind's talk of nuclear cooperation with France, which also has its own national deterrent with more than 400 warheads but, unlike Britain, has been showing few signs of wishing to limit it significantly.
Menzies Campbell, defense spokesman for the Liberal Democrat Party, says working with France on nuclear matters ``makes considerable sense.'' But he believes it should be seen as a step toward a common European foreign and security policy, not as mere ``bilateral arrangement.''
The opposition Labour Party has been keen to keep a low profile on questions of nuclear defense. In the 1980s it favored unilateral nuclear disarmament, but has since softened its position.