LONDON — THE future of Britain's Trident nuclear deterrent has been dealt a blow by President Clinton's call for an extension of a moratorium on nuclear tests at least until September of next year.
Prime Minister John Major plans to raise the issue at the current Group of Seven summit meeting in Tokyo. He will argue that denial to Britain of nuclear test facilities in Nevada will hamper the development of a new warhead for its Trident missile arsenal.
London officials, however, concede that the chances of changing Mr. Clinton's mind are minimal. They also note that France, which has its own nuclear force, is veering toward support for an extended test ban. This would leave Britain isolated.
A British official said that new warheads, due to be fitted to four British-built Trident submarines, would probably have to be validated by some other means, such as computer simulation.
Malcolm Rifkind, Britain's defense secretary, said on July 4 that there was a need to ensure "the highest possible level of safety and reliability" for the Trident fleet's nuclear missiles. Testing in Nevada was the best way of ensuring this, according to British officials.
Britain has tested its own nuclear devices in the Nevada desert since 1962. It has no other test site.
US officials in London said Clinton has told the prime minister that failure to extend the moratorium would encourage testing by Russia, China, and France and give third-world countries an excuse to pursue their own nuclear-weapons programs. The officials said Clinton is aiming to achieve renewal of the Nuclear Non-Proliferation Treaty in 1995.
IN the early 1980s, Britain's determination to remain a nuclear power meant that it had to replace its existing Polaris fleet of four submarines with a force equipped with US-supplied Trident missiles.
The planned four-submarine Trident force will cost British pounds10 billion ($15.1 million) and becomes operational in 1995, with a planned operational life of 25 years. It will be able to carry nearly three times as many warheads as its Polaris counterpart.
Britain has insisted on designing its own warheads, but so far this has meant using US test facilities.
Arguing Britain's case to be allowed to continue testing, Major reportedly told Clinton that the new warheads were needed to make the Trident force more flexible in its response to crises.
Earlier multiple warheads were designed for possible strategic use against the former Soviet Union. The current design, defense sources say, could be used in response to localized sub-strategic crises in, for example, the Persian Gulf.
One possible option open to Britain is to seek an agreement with France to be allowed to use its test site in the South Pacific. But this would threaten to widen the growing rift between Britain and the US.
Major's nuclear dilemma has been magnified by pressures from his own defense establishment. The government was expected to cancel plans to construct a new generation of diesel-electric submarines. British defense chiefs had earlier agreed to this, but only on condition that the Trident fleet was equipped with a new warhead for possible use in localized conflicts.