The invasion of Afghanistan jeopardizes the Soviet's already strained trade and arms- control relations with the United States, say American experts on US-Soviet affairs.
Indeed, some of these experts say that, barring the unlikely event of a rapid Soviet withdrawal from Afghanistan, the Soviets' military intervention in that country has guaranteed, for some time to come, a return to a cold war atmosphere between Washington and Moscow.
As one congressional staff aide sees it, Senate ratification of the US-Soviet SALT II treaty to limit nuclear weapons now will depend on a credible Carter administration response to Soviet actions in Afghanistan. Even then, given growing antipathy in Congress toward the Soviets, there would be no guarantee of ratification. President Carter would have to commit himself to personal leadership of a major battle for Senate approval.
Republican Party national chairman Bill Brock has declared that, given the Soviet invasion, the ratification of SALT II would be "unthinkable."
Administration officials said the President had not changed his mind about the merits of the SALT treaty but indicated that he may delay submission of the treaty to the Senate. The administration had expected to submit the treaty this spring.
Beyond SALT, much may also be riding, in a political sense, on the President's response to Afghanistan.Some observers think that by declaring in an interview here on New Year's Eve that Soviet President Leonid Brezhnev lied to him about Afghanistan, Mr. Carter left himself open to the charge from his political opponents that he has been naive in his dealings with the Soviet leadership.
"I think we're back to the cold war -- at least through 1980," says one American expert on Soviet affairs.
"I'm going to put on my helmet and lie low for a while," says another expert whose job it is to promote US-Soviet trade relations. "The right wing is going to have a heyday around here."
In the midst of such an atmosphere, some of the President's options appear to be simple. To start with, officials say, Mr. Carter is likely to seek condemnation of the Soviet Union at the United Nations, cut the sale of high technology to the Soviets, and resume arms supplies to Pakistan, the country that appears to be most immediately threatened by the Soviet intervention in Afghanistan.
But beyond that the options get more complicated. A cutoff of wheat sales to the Soviets might bring protests from the Midwestern farmers who benefit greatly from them. And unless other big grain suppliers, notably the Australians and Canadians, can be made to go along, such a cutoff might prove ineffective.
Secretary of Defense Harold Brown's trip to China starting Jan. 5 has been given added impetus by the Soviets' actions in Afghanistan. One question being asked in Washington is whether the US should develop a strong "security relationship" with China, given Moscow's growing military strength and assertiveness. The defense secretary is expected to discuss with the Chinese the possible sale to their country of high-technology items such as satellites and computers that are designed for civilian use but can be converted to military purposes. Some such sales already have been made.
The Soviet action in Afghanistan also has added urgency to discussions in Washington now taking place concerning a recently returned mission by US State and Defense Department officials to the Middle East and Africa. The officials were seeking increased American access to naval and air bases in Oman, Kenya, and Somalia. Undersecretary of State David Newsom would not comment on the result of the mission other than to say that the officials "generally had favorable responses" in the countries they visited.
Another sensitive option said to be under discussion by the President and his advisers concerns the possible supply, through Pakistan, of weapons to the Muslim guerrillas who are battling the Soviets and the government they support in Afghanistan. Some American experts note that if the guerrillas were provided with hand-held, heat-seeking missiles that could be used against Soviet helicopters, it might change the nature of the Afghan war.
One expert, who asked not to be identified, predicts the US will almost certainly get into the business of helping to supply the rebels at some point. But he notes that the guerrillas are not only badly divided but also adhere to beliefs and attitudes that are not compatible with American values.