Two former secretaries of state in Republican and Democratic administrations endorsed the new U.S.-Soviet nuclear arms treaty yesterday as the Defense Department urged Congress in a report to lift restrictions on new nuclear missiles and artillery shells for deployment in Western Europe.

In the sharpest warnings thus far about the consequences of rejection or crippling amendments, William P. Rogers, who served under President Richard M. Nixon, and Cyrus R. Vance, who was secretary under President Jimmy Carter, urged approval of the Intermediate-Range Nuclear Forces (INF) Treaty without changes.

Vance, who helped negotiate the unratified 1979 SALT II treaty, was joined in support of the INF pact by retired general Edward L. Rowny, who resigned as an arms-control official during the Carter administration in opposition to the SALT II agreement and now serves as a special adviser on arms control under President Reagan.

The Pentagon's report on the military impact of the INF Treaty said Congress should allow development of a new nuclear-tipped Army tactical missile system, which would replace the aging Lance missile now deployed in five European countries.

The report, demanded by the Senate in last year's budget bill, also called on Congress to lift restrictions on additional production of nuclear-tipped artillery shells, and to provide new funds for nuclear bombs and missiles to be deployed on aircraft based in Europe.

Although such deployments are expected to arouse controversy in Europe, Secretary of Defense Frank C. Carlucci suggested in an introduction to the report that his endorsement of the INF Treaty was based in part on the expectation that Congress would approve these and other improvements to U.S. nuclear and conventional forces.

"Before entering into our agreement . . . we made sure . . . that NATO's resulting forces structure would be fully capable of supporting deterrence -- provided {emphasis in original} that we vigorously pursue the necessary modernization," Carlucci said.

The report noted that the North Atlantic Treaty Organization has not yet decided how to "readjust" its nuclear forces in the wake of the INF Treaty. But it said Carlucci was "prepared to ensure a high priority for all aspects" of a nuclear modernization plan.

Soviet Foreign Minister Eduard Shevardnadze last week strongly criticized NATO discussions of new nuclear weapons, contending that they could "scuttle everything that has been achieved in the sphere of nuclear disarmament."

Shevardnadze said in Bonn that "this must not be permitted."

U.S. officials have taken pains in Senate hearings this week, however, to emphasize that nothing in the treaty blocks any U.S. nuclear modernization.

In the Foreign Relations Committee room yesterday, Sen. Jesse Helms (R-N.C.) continued his wide-ranging assault on the treaty amid mounting efforts by colleagues to blunt his charges, contributing to heightened tensions among committee members and a testy exchange between Helms and the panel's Democratic majority.

In response to Helms' charges that provisions allowing reuse of warhead components in missiles to be destroyed under the treaty violate Reagan's goal of weapons reduction, Sen. Alan Cranston (D-Calif.) said the Reagan administration had insisted on saving nuclear explosive and guidance devices to keep U.S. nuclear secrets out of Soviet hands.

Otherwise, Soviets would have "free rein" inside critical U.S. nuclear reactors, processing plants and bomb design and assembly facilities, including reactors in Helms' home state, said Cranston. "The American people aren't dumb. They aren't about to believe that Ronald Reagan, our most virulently anticommunist president, has been snookered by the Soviets," he added.

When Helms quoted 1987 testimony about a communications intercept in which former Soviet leader Leonid Brezhnev appeared to be stretching treaty language to accommodate a new Soviet missile, Sen. Joseph R. Biden Jr. (D-Del.) suggested it showed the Soviets were trying to avoid outright violations and added that the testimony may have involved classified information.

Helms, who was not present during Biden's comments, returned later to assert Biden was implying falsely that Helms was violating official secrecy and suggested that Biden was "overstepping . . . propriety." Helms said he was reading from published testimony at an open hearing last year. Other Democrats rallied to the absent Biden's defense, saying the initial testimony may have involved a breach of secrecy.

The testimony of Rogers and Vance appeared aimed at overpowering specific criticisms of the pact with an all-encompassing embrace stressing the pitfalls of tampering with the treaty, which Reagan and Soviet leader Mikhail Gorbachev signed last month to eliminate medium- and shorter-range missiles in the superpowers' nuclear arsenals.

"The political effects within the {NATO} alliance of our being unable to go forward at this time would be absolutely disastrous" and pose "very grave consequences for any arms control negotiations in the future," Vance said.

"I agree with that, and I'd go further," said Rogers, who contended the consequences would be global. "A lot of people in the world think we're warmongers, that we are equally as guilty as the Russians in terms of wanting to dominate the world," he said, adding that it would be "devastating" if a few senators could block a treaty in light of its otherwise broad support in the West.

"I can't think of a more serious setback to American foreign policy and to American interests throughout the world than to have this treaty fail . . . , " said Rogers, who was instrumental in negotiation of the SALT I and Antiballistic Missile (ABM) Treaty in the early 1970s.

The former secretaries were also joined by Rowny and David M. Abshire, former U.S. representative to NATO, in cautioning against trying to amend the treaty or link it to other issues, such as strengthening NATO's conventional forces.

"I think Congress will make a terrible mistake if it permits any amendment or resolution," said Vance. "Once you get one, you get a Christmas tree and before you know it, you get a killer."