Britain's antinuclear protesters fight on

Anti-cruise-missile peace protesters are down - but not out. That is the situation NATO countries faced as Defense Secretary Michael Heseltine held his first talks with his US counterpart Caspar Weinberger in Washington.

Debate about the future of the peace movement in Britain has, in fact, been getting louder recently. Government ministers spread their view that the movement is a spent force.

Protesters admit that life is more difficult now than in the euphoric days earlier this year, and that they cannot physically prevent cruise missiles arriving at Greenham Common in Berkshire by December. But they predict a lively autumn and winter of headline-catching demonstrations, and public pressure to keep the antinuclear issue alive.

Protests are planned on Oct. 22 across Europe. The British movement will draw strength - or suffer - from the efforts of West German groups, which are up against the pro-US stance of Chancellor Helmut Kohl.

Here, Tory government ministers encourage the view that the debate over unilateral disarmament was virtually ended when Prime Minister Margaret Thatcher was resoundingly reelected last June 9.

Today, even some elements of Labour's unilateralist left suggest a referendum might be needed before a future Labour government discards the Trident submarine missile program. Mr. Heseltine, it is argued, has been more effective than his predecessor, John Nott, in presenting the government case.

The Defense Ministry has loosed a propaganda barrage, announcing closure of ''Defense Secretariat 19,'' a ministry unit set up to counter the Campaign for Nuclear Disarmament (CND). In fact, pro-cruise campaigns have been transferred to other departments.

Divisions remain within the CND, one of Europe's most vigorous peace groups. The majority want protests at a mass rally Oct. 22 and at the Greenham Common air base in Berkshire later in the year to be ''symbolic.'' They urge that links be forged with the US nuclear freeze movement.

Others see any lessening of commitment to complete disarmament as a ''sell-out.''

Meanwhile, the CND claims its fight is still being strongly waged. ''Our national membership is still rising, to about 70,000 now,'' says Alison Whyte. CND cites the recent formation of two new pro-cruise lobby groups, one of clerics and one of academics, as proof it remains vital.

The CND continues to be controversial. Its general secretary, Monsignor Bruce Kent, has been criticized for urging British soldiers not to obey orders associated with nuclear weapons. He replies that Dutch soldiers are permitted to disobey such orders.

And Mr. Heseltine is still wary of CND. He will not announce when the first cruise missiles will arrive at Greenham Common. One reason is to avoid tipping off CND protesters.