It is urgent to develop a more effective American policy against terrorism. Americans in particular are increasingly the victims of this ugly phenomenon. From the hostages in Iran five years ago to the most recent ordeal in Beirut, a lengthening shadow has been cast over the U.S. presence abroad. Why are we so often the targets? Surely not because we are weak. Since World War II, our nuclear and conventional forces have been largely successful in deterring outright aggression. Paradoxically, precisely because we are strong, the terrorists and their allies seek to chip away at our morale, our domestic order and our international prestige -- the shadow of our power, as Dean Acheson put it.

Precisely because we are democratic, because we believe in individual rights, the terrorist method is to pit our reverence for innocent life against our natural instinct to defend ourselves. And it is precisely because we believe in an international order, in which necessary change can take place peacefully, that terrorists find their natural allies among those who wish to remake the world forcibly in their own totalitarian image.

Why have we been unable to act more effectively against terrorism? Three important fallacies cloud our thinking.

First is the fallacy that terrorism lives on its own organic resources, independent of state aid. We must be able to discriminate, of course, among the acts of deranged individuals, obscure groups possessed by violent political doctrines and the full-fledged agents of government.

Yet difficult as this may be, one thing is easy to discern: terrorism's success breeds growing support. Libya, Iran and Syria employ terror because they believe it works. The Soviet Union, sometimes through East Germany and Bulgaria, bears a heavy responsibility. All of these states want political change by force; they want to turn the balance of power against the democracies.

State-sponsored terrorism is but one element along a spectrum of violence intended to transform the international order. If we forget this, then we are bound to miss the larger issue -- the difference between democratic and totalitarian regimes with respect to international change.

Second comes the moral fallacy that somehow counterterrorist action, which may risk innocent lives, "dirties" our hands. This fallacy condemns us to paralysis and puts the terrorist and his victims -- and the United States is a victim -- on the same moral plane.

The use of force may miscarry. Military operations do go awry. But the alternative to risking a few precious lives today may be to risk many more no less precious lives tomorrow, as terrorists and the governments that support them become convinced that we lack the moral strength to defend our values.

This fallacy has just about crippled our debate over terrorism. We see senior U.S. officials threatening preemption when we have yet to succeed at retaliation, and setting forth conditions for the use of our military forces so ideal that they have rarely been met even in wartime. All this talk only increases the pressure for ill-considered action in the hope of recovering a self-damaged sense of virility.

The third fallacy is the fear that concerted action against terrorism or its state sponsors somehow sacrifices more important issues. A case in point: the fear that a full expos,e of the plot to kill the pope may complicate efforts to reduce tensions with the U.S.S.R. Another case in point: our curious silence over the Syrian role in terrorism after our departure from Lebanon. Obviously, we must be prudent in dealing with such states sponsoring terrorism, but prudence can never be an excuse to avoid the truth.

We must deter terrorism by lowering the rewards and raising the penalties for those who encourage it. This includes both improved intelligence and more effective defensive measures. CIA Director William Casey has correctly emphasized improved human sources of intelligence.

The most important initiative, however, is to rally concerted international action: political, economic, diplomatic and military. It works. Libya's Muammar Qaddafi was forced onto the defensive in 1981-82 by such measures until nearly everyone resumed business as usual. But we are under no obligation to adhere to a multilateral suicide pact if international action is not forthcoming. Then we must act alone.

In the final analysis, our character as a free people is being tested. Are we too irresolute, too concerned with the ebb and flow of public opinion, too "short of breath" as the Syrians boasted following the Marine withdrawal? I think not.