WASHINGTON — President Reagan and Soviet leader Mikhail S. Gorbachev, concluding their historic third summit meeting, announced significant progress Thursday toward a treaty to slash in half the superpowers' awesome arsenals of long-range nuclear weapons.
They claimed no breakthroughs on human rights, Afghanistan and other regional trouble spots. But they insisted that their time spent together--5 1/2 hours in business meetings and eight more hours in social occasions--would advance the cause of world peace.
Reagan, in a nationally televised speech that began just as Gorbachev lifted off from Andrews Air Force Base in his Ilyushin jetliner, said, "We have put Soviet-American relations on a far more candid, and far more realistic, footing."
Earlier Gorbachev, during a lengthy, rambling press conference at the Soviet Embassy compound, asserted, "I would even venture to say we trust each other more."
The President said he and Gorbachev agreed to meet again in Moscow in several months "to continue what we have achieved in these past three days. I believe there is reason for both hope and optimism."
U.S. officials said they expect the next summit in May or June.
Gorbachev, speaking mostly from notes to 350 invited journalists, said he hoped that the two men could use that occasion to sign a treaty reducing long-range, or strategic, nuclear weapons. U.S. officials said the treaty signing, however, was not a condition for the summit, which would be the fourth between the President and the general secretary of the Soviet Communist Party.
Reagan said he and Gorbachev made "real progress" toward the goal set during their first summit in Geneva in 1985: "to achieve deep, 50% cuts in our arsenals of those powerful weapons." And a senior Administration official said the Soviets made a "significant" concession on missile defenses.
A joint statement issued by the two sides at the end of the three-day meeting outlined three major areas of agreement on the road to reducing long-range offensive weapons--land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles and bombers carrying cruise missiles:
-- A limit on each side's combined ICBMs and submarine-based ballistic missiles of 4,900. The two sides had already agreed that the three categories of weapons--including bombers--would be reduced to 6,000. The sub-limit, a compromise between the U.S. goal of 4,800 and the Soviet position of 5,100, reflected the U.S. effort to restrain the Soviets' large force of heavy missiles.
-- In the area of verifying compliance with the treaty, agreement to establish procedures that build upon those of the accord signed by Reagan and Gorbachev on Tuesday to eliminate medium-range missiles. Those procedures, the most intrusive ever accepted by the Soviets, allow inspectors from each side to be stationed permanently on the other's soil.
-- Limited agreement on the technically complicated question of how each side's long-range nuclear weapons would be counted.
At the same time, however, a senior Administration official who asked not to be identified conceded that "there are some very thorny issues remaining" on the questions of verification and counting. And the United States could not persuade the Soviets to agree to a sub-limit on the two sides' ICBMs, the weapon upon which the Soviets rely most heavily.
Gains on Defensive Weapons
Progress on defensive weapons--chiefly Reagan's space-based Strategic Defense Initiative, popularly known as "Star Wars"--was no less significant, according to Administration officials. There were these accords:
-- The two leaders instructed their arms negotiators to reformulate the 1972 Anti-Ballistic Missile Treaty so that its provisions would extend for an unspecific period--up to seven years as sought by the United States and 10 in the Soviet position. The Soviets withdrew their insistence that they would not sign a treaty limiting offensive weapons without an agreement restricting SDI.
-- During the seven to 10 years, according to the joint statement, the two sides could conduct "research, development and testing" of space-based defensive systems "as required." Previously the Soviets had insisted that the ABM Treaty prohibited testing in space.
-- After the seven to 10 years, each side would be free to deploy space-based defenses unless both had already agreed that deployment would be prohibited. Previously the Soviets had sought to keep the non-deployment period in force indefinitely.
"Nothing that was done today," he said a senior Administration who asked not to be identified, "restrains U.S. or Soviet research, testing or development."
Even before Reagan and Gorbachev wound up their final working session, Kenneth L. Adelman, outgoing director of the U.S. Arms Control and Disarmament Agency, expressed surprise at the degree of progress.