QUICK, SAY the Pakistanis: the Soviets have escalated from private to public threats against us for sheltering Afghan resistance fighters, and they may support restive frontier ethnics or even invade. Yet you Americans keep backing away from making good, with fresh supplies of sophisticated arms, on your pledges of support. You don't even let us in on decisions you are making with others, like China, affecting our fate. We are a small, exposed country and, if we do not get a significant military and economic infusion promptly, we may buckle -- to your dismay as well as ours.

Careful, say the Indians: the Zia regime in Pakistan is crude and undemocratic, it has scant popular or non-Punjabi support, and it may accept arms from Washington in the name of containing Soviet power only to use them against India. Pakistan is too weak and too Islamic to be a reliable friend. And why, after all, should the United States bolster Pakistan? The Pakistanis, who had helped the Afghan Islamic rebels, may wonder now -- and with some reason -- if they will have to pay; but the best thing is to simmer down.

This is the argument on the Asian subcontinent now; it may be pressed with special vigor on the Indian side by the newly reelected Indira Gandhi. It is reflected in a parallel debate going on in Washington. The United States is being asked to show steadiness in the larger crisis by launching a new program of military (and economic) aid for Pakistan and by updating its old commitment to weight in if Pakistan is attacked. Not to respond forthrightly to Pakistani alarms risks conveying the notion that the United States is dragging.

Yet crisis aid, especially if it involves the sophisticated equipment more useful against a major army (like the Soviet Union's or India's) than against the likelier threat of an insurgency, can create its own complications. Then there is the matter of Pakistan's quest for its own nuclear bomb; by dropping its military-aid condition that Pakistan forswear the bomb, the administration undercuts its nonproliferation goals in both Pakistan and India. Nor can the Zia Regime's own priorities be ignored: a few weeks ago the regime felt it wise to wait for six hours, until the 100 occupants were near being cooked alive, to relieve a mob's siege of the American Embassy in Islamabad.

One answer to these dilemmas is to allow the pluses and the minuses to cancel each other out and, with a certain coldbloodedness, to do essentially nothing. That is the wrong answer. The right answer is to accept Gen. Zia for what he is -- the man running Pakistan now; to give his regime the kind and amount of help that will make plain that the United States understands its larger stake in the security of Pakistan, and then -- eyes open -- to try to limit the collateral risks. That the choices are painful does not mean they can be avoided.