Even A-Arms May Be Futile, NATO Warned : Report to Defense Chiefs Urges Narrowing of Gap in Conventional Weapons

North Atlantic Treaty Organization defense ministers were warned Wednesday that if the Western allies fail to narrow the gap in conventional weapons between NATO and the Soviet Bloc by the year 2000, Western Europe could be open to an attack so sudden and successful that nuclear weapons might be useless as a countermeasure.

The warning came in a report, prepared by the alliance’s military committee, that received preliminary approval from the defense ministers, according to Richard N. Perle, U.S. assistant secretary of defense for international security.

The defense chiefs met here in two brief sessions, racing through a two-day agenda in a day and a half.

‘Threat Great, Growing’

“The assessment of the report is one the authors fear will come true if NATO doesn’t make a response,” Defense Secretary Caspar W. Weinberger said. “I don’t think there should be any confusion about the Soviet threat. It is very great and it is growing.”

The document, which has not been made public, will be reviewed by each nation’s permanent representative to NATO and will be presented for formal adoption by the defense ministers next winter.

A U.S. defense official, reviewing the concerns raised in the report, said, “The whole key to the use of nuclear weapons is that you still have a cohesive defense.”

The official, speaking on condition that he not be identified by name, said nuclear weapons would be useful only if the Western defenders, by using them, could achieve significant military goals or could increase the likelihood of negotiations. A sudden and effective Soviet strike from the east, he said, could remove any tactical role the weapons might play because Moscow would already have achieved its military goals in Western Europe.

Top General’s Proviso

The United States has maintained that it would not initiate a military attack. However, Gen. Bernard W. Rogers, the NATO commander, has said that the West’s conventional warfare deficiencies could force him to seek permission to use nuclear weapons within days of a Soviet attack.

Perle said the report could be seen as “a pitch for improving conventional forces,” a main focus of American officials now that NATO’s arsenal of medium-range nuclear weapons is being modernized with the deployment of new U.S. Pershing 2 and cruise missiles.

He also said there is confusion as to whether the Soviets are capable of launching an attack without providing such warning signs as the call-up of reserves and the mobilization of other forces. But a senior NATO official, also speaking on the condition of anonymity, said, “The Warsaw Pact has been improving and increasing its ability to attack without warning.”

One of the issues that Pentagon officials had expected to cause trouble here for Weinberger--the difficulty the Reagan Administration is having winning support from Congress for a larger defense budget--was dismissed with little debate.

The United States was successful in keeping NATO committed to annual increases by member nations of 3% in defense spending after inflation.

Allies’ Reluctance

“There were no expressions of concern, in part because a lot of the allies are not well-positioned to complain about U.S. defense spending,” Perle said, referring to the failure of some other NATO members to meet the goal of 3% growth.

The British, who have met the target in the past, now say they will not be able to increase their arms expenditures by that amount in the future, U.S. officials note.

The Reagan Administration’s “Star Wars” space-based missile defense proposal, formally known as the Strategic Defense Initiative, received little consideration at the meeting here. Part of the reason for that, officials said, was that the proposal was the focus of a March meeting of the defense ministers in Luxembourg.

At that session, Weinberger invited the allies to take part in “Star Wars” research and caused a stir by appearing to give them a deadline to submit their applications for participation.

Since then, seven European members of NATO have had difficulty trying to agree on a unified response to the invitation. (In Paris on Wednesday, top-ranking West German and French officials agreed to hold a special meeting on the matter, German Foreign Minister Hans-Dietrich Genscher told the Reuters news agency. No date was set for the session.)

As a result of the speed with which the defense ministers dealt with the items on their agenda, Weinberger planned to leave Brussels early today, advancing his return to the United States by half a day.