MOSCOW -- The United States and the Soviet Union agreed yesterday to end arms shipments to the warring sides in Afghanistan Jan. 1, removing the crucial element of superpower supplies from the 12-year-old civil war.
The two sides said they would push for a cease-fire, a cutoff of arms from other sources and free elections after Jan. 1, according to their official joint statement. They also agreed not to accelerate their own arms shipments before the cutoff.
Both two major Afghan opposition groups and Afghan President Najibullah welcomed the cutoff proposal.
The agreement, announced here by Secretary of State James A. Baker III and Soviet Foreign Minister Boris D. Pankin, is the latest in a flurry of diplomatic breakthroughs since the collapse of a coup in August undermined hard-line influence on Soviet foreign policy.
Even though the Soviet Union pulled its troops out of Afghanistan in February 1989, it has continued to supply arms in large quantity to the Communist regime of Dr. Najibullah. The 10-year Soviet military involvement, in which more than 15,000 -- Soviet soldiers died, is now assessed here almost universally as a mistake and misadventure.
Many Western diplomats and area specialists had predicted that Dr. Najibullah would fall shortly after the departure of Soviet troops, but his rule has proved more resilient than expected. The United States has kept up large-scale shipments of arms to the opposition and the war has ground on, costing thousands of Afghan lives and resolving nothing.
Since the Soviet coup fell apart Aug. 21, Moscow has declared what amounts to a diplomatic fire sale, rushing to remove the remaining obstacles to full East-West cooperation and thus encourage large-scale economic aid during the transition to a market economy.
First, returning chastened and weakened after his three-day captivity at the hands of the coup leaders, President Mikhail S. Gorbachev dropped his objections to complete independence for the Baltic republics of Estonia, Latvia and Lithuania. The United States and most other Western countries had never recognized the Soviet annexation of the three republics in 1940 and had long backed their independence.
Then, after meeting Wednesday with Mr. Baker, Mr. Gorbachev casually told reporters that the Soviet Union intends to open negotiations with Cuba on the removal of Soviet troops from the island. The Soviet military presence 90 miles from the Florida coast is an old irritant in relations with the United States.
Mr. Baker explicitly linked the three shifts of Soviet policy in his comments yesterday.
"This removes three of the most contentious old-agenda issues that have impeded and obstructed progress. I'd like to say I'm delighted these have been removed," he said.
Mr. Baker had a friendly meeting yesterday with Vadim Bakatin, the post-coup chief of the KGB and heard Mr. Bakatin give assurances that the Soviet Union no longer sees the United States as its adversary and hence will do less spying.
Changes are coming daily. On Thursday, Mr. Gorbachev fired two deputy chiefs of the KGB, apparently because he found evidence that they were involved in the coup. Yesterday, Mr. Bakatin dissolved the KGB unit that monitored religious organizations.
In a meeting with Gen. Vladimir Lobov, chief of the Soviet general staff, Mr. Baker proposed yesterday that talks begin soon to cut the superpowers' tactical nuclear arsenals.