Afghan Rebel Gains Against Soviets Reported by U.S. Aide

U.S.-backed Afghan insurgents have inflicted the highest casualties ever on elite Soviet troops trying to cut off guerrilla supply routes along the Pakistani border during the past six weeks, according to a senior official of the Reagan Administration.

The official described the fighting as the most intense since the rebels began opposing the Marxist government installed in a 1978 military coup. Soviet troops invaded Afghanistan in December, 1979, to support the government.

The latest fighting comes against the backdrop of apparent determination by both the United States and the Soviet Union to intensify the military confrontation even as long-term maneuvering has begun for a possible political settlement.

The official said that the Administration is determined to increase the amount and sophistication of American weapons supplied to the insurgents until Washington sees “serious indications” that the Soviets are ready to withdraw their troops, estimated at 115,000.

“What we’re doing is matching,” said the official, who took issue with Soviet complaints about the recent supply of U.S.-made Stinger anti-aircraft missiles to the Afghan insurgents.

During the first two weeks of June, he said, the insurgents killed or wounded between 250 and 300 Soviet special forces, or spetsnatz, and shot down 15 Soviet or Afghan aircraft around Ali Khel in Paktia province in eastern Afghanistan near the Pakistan border.

The Soviets lost 120 special forces between May 23 and June 5 in the same area where they tried to occupy a guerrilla supply route from Peshawar, Pakistan, he said.

This year’s fighting follows a pattern of escalation that began with last year’s Soviet offensive, which included new Soviet tactics, more sophisticated weapons and highly mobile spetsnatz units.

The Soviet escalation was one important factor in the Administration’s decision to send Stingers to the insurgents. The rebels received 150 Stingers late last summer after selected units were trained to use the shoulder-fired missiles. They were sent another 600 this year.

To the surprise of U.S. analysts, there is still no evidence the Soviets have devised countermeasures to protect their aircraft from the Stinger, whose guidance system homes in on infrared or ultraviolet energy rather than the heat emitted by a plane’s engines.