For years experts and commentators talked about the importance of America's technological advantage in military hardware.

The Persian Gulf war decisively demonstrated the truth of their observations. Intelligence has taken on a new meaning in warfare. It applies to the weapons - and to the people who wield them.What we saw during the war is just the beginning of what we are likely to see in years to come. Silicon-based information-processing devices are likely to give way to computers that exploit the special properties of light interacting with new crystalline materials, thus permitting information processing at speeds thousands of times faster than existing machines.

Today - more than ever before - it seems that properly applied knowledge is power. Yet by itself neither the knowledge nor the power it helps to create guarantees good results. I think the recent little flap over President Bush's decision to halt the ground war when he did is a good illustration of the point.

Surely we had the power to destroy Saddam Hussein's military machine so completely that he would have no chance of maintaining control in Iraq. However, if we had exercised that power, what would stand in the way of Iraq's disintegration into chaos?

Well, we could have moved in to occupy the country, and depose Saddam. Then we would have inherited the political problems, particularly with the Kurds, that are now tearing the country apart.

Did we want responsibility for caring for and rehabilitating the country that Saddam's aggression ruined?

If we had taken on that responsibility it could have proved the first fateful step toward empire building in the classic sense. I think we would have found that, unlike Japan or Germany at the end of World War II, Iraq would not easily have let us go. Unable to pacify the country fully, and unable simply to back out of the responsibility we had assumed for its people, we might have confronted the prospect of a long period of increasingly difficult occupation.

The president weighed what we had the power to do against what we had a compelling interest in doing, and chose to restrain our power. By doing so he may have taken a step in the direction of keeping the American republic from the fate of others before us, whose power created situations that impelled them toward empire.

He acted in a tradition that in fact goes back to the great restraint that America showed the last time science gave us a decisive military edge, at the dawn of the nuclear era. For a moment we monopolized the thunderbolts of which conquerors like Napoleon dreamed.

Our restraint then may help to explain why the world avoided nuclear war long enough to bring us to an era when the prospect of such a war has begun to recede. Our new technology may be revolutionizing so-called conventional war in ways as decisive as, and far more usable than, nuclear weaponry.

Despite the temptations of this power, restraint may also be the course most likely to enhance the long-term prospects for peace. It may mean doing less good in the short term than we might wish, but in the long run I believe it will contribute to the most important kind of co-existence - one between great power and lasting republican freedom.