THE INTERVENTION of Soviet troops in Afghanistan, ostensibly at the request of the Afghan government, was an act of international aggression rightly condemned by American leaders, their allies and several Third World governments.

No leap of the imagination can substantiate charges by Tass, the Soviet press agency, that the presence of 50,000 Soviet troops in Afghanistan is a response to American "cold war" policies. Whether Soviet leaders decided to move in on Afghanistan because they feared the Moslem rebellion there would spread to the large Moslem minority in the Soviet Union, or whether the intervention is the first step in Soviet expansionary designs on the Middle East, the act shows the bankruptcy of Soviet claims to be the Third World's benefactor.

The measures President Carter has taken thus far to register American outrage at the intervention--economic responses, including reductions in grain sales and high technology assistance, and symbolic responses, like the reduction in embassy staffing--make their point well enough: that if Soviet leaders resort to military force to pursue their interests abroad, they will forfeit many of the benefits of detente. Food should not be used as a political tool when its denial might cause starvation, but in this case Carter's action will demonstrate to the Soviets that America is willing to sacrifice profitable grain deals in protest.

But to oppose ratification of SALT II because of the events in Afghanistan is to invite further Soviet aggression by telling the Soviet Union that heightened military competition is what the United States wants. To delay the arms limitation debate in the current sabre-rattling climate may be a wise tactical move for Carter; but SALT and the years of negotiation it represents are still the best hope for world peace. Dumping the treaty now would neither hurt the Soviets nor further U.S. interests.

The Pentagon has used the emotions aroused by the Soviet aggression to win agreement on military spending increases that would otherwise be unthinkable; especially in an inflationary economy. The bloated military establishment needs more discipline, not more money. Experience proves that added billions for more military hardware do not guarantee the safety of American interests abroad.

THE UNITED STATES is at a crossroads in its foreign policy: it can either re-subscribe to the principles that brought two decades of cold war, Korea and Vietnam, or try something new. The old policies have brought nothing but failure; if, for once, the U.S. shuns a knee-jerk military response, it will both salvage its foreign policy goals and leave open a path to world peace.

The United States should not supply arms to the Moslem rebels in Afghanistan, whatever the merits of their cause, and should not start selling arms to Pakistan, a military dictatorship which may well be working on its own nuclear system. Instead, the U.S. should take the crisis as a chance to show its Third World critics that it does not always live by the sword.

If the Soviets confirm the charges of cold warriors, who say the Afghanistan invasion is part of a master-plan to seize Middle Eastern oil, then America will have to face the possibility of military responses. But no vital American interests have been threatened in Afghanistan, which has had a pro-Soviet government for two years now. If the Soviet troops leave Afghanistan once their puppet government is secure, all the military rhetoric being spouted today in Congress and the White House will look ridiculous. Afghanistan offers us a clear choice: old reflex responses that got us into our present bind, or new approaches that leave some way out.