President Bush says that a new world order is at stake in the war against Iraq. Yet no matter how the war comes out, a new world order - an era of universal peace and security, to use the president's description - will be impossible so long as the Middle East remains the most dangerous place on Earth.

That is, the postwar face of the Middle East will greatly determine whether the world moves forward toward stability or whether it remains stuck in an old order defined by suspicion, hatred and periodic bloodshed. And the face of the Middle East, in turn, will depend on how the war ends.Only partially can the United States control the crucial end game. It is important for Americans to understand the limits of the military to affect the political environment in the Persian Gulf, to be aware of how much leverage may remain with Saddam Hussein or his successors and to appreciate the urgency to plan for the various eventualities that will follow the end game.

Unless the last is done intelligently, and there is little visible evidence of it so far, the United States may well lose the peace. I say the United States instead of the allies because what Washington desires from the postwar Middle East will be considerably different from what Syria or Saudi Arabia wishes for the region. Saddam's Iraq, at bottom, is only a product of the historic destabilization there.

The end game possibilities are almost innumerable. What follows are 10 variations on four basic themes, each of which produces a different set of problems and opportunities for the United States.

This is the first theme and worst case: The allies lose. Either through a dramatic defeat (the implausible Dien Bien Phu of the desert) or the long, bloody passage of time, American political backing for the war dissipates and the fighting ends. The first variation involves a face-saving negotiation that leaves a significant U.S. presence in the Mideast. The second supposes that we say to heck with it and come home. Depending on which takes place, the consequences for the Mideast will be quite different. Both, however, leave Saddam as a force, with the latter keeping him a threat to strike again.

The second theme envisions Israel drawn into the war. Obviously, the future of the Middle East will be vastly different if the Arab allies turn on Israel, resulting in a wider, different war than if the coalition holds together against Iraq. But in either case, Israel will have a hand in dictating the postwar terms, as it might not had it stayed out.

The following two themes seem the likeliest. In the third one, the allies win but without removing Saddam from the scene. Here are three variations: The Iraqis withdraw from Kuwait and Saddam licks his wounds; the allies successfully invade Iraq, forcing Saddam to the sidelines and ending Iraq's status as a regional power; and defeated on the battlefield, Saddam defiantly carries on through guerrilla warfare or other unconventional means. Each of the three presents its own set of implications for the future of the Middle East.

Under the last basic theme, the allies win and Saddam is dead, imprisoned or exiled. Hence, the following variations: With Kuwait liberated and Saddam gone, a pro-Western government takes possession of a reasonably healthy Iraq; wasted by invasion, a prostrated Iraq becomes a ready victim for the next regional adventurer; and radicalized and unrepentant, Saddam's successors continue to export terrorism. Again, each outcome produces its own equation for the region.

A few of these variations are farfetched, and the differences between some of them are slender. Be that as it may, the ones listed here by no means exhaust the possible ways in which the war might be concluded. No matter how subtle the distinctions among them, the fact is that each variation would lead the future of the Middle East in a direction of its own. Each would require a different political response.

We delude ourselves if we imagine that a successful prosecution of the war will have an immediate, conclusive effect in the Middle East. The historic enmities will remain, as will dictatorships almost everywhere except in Israel. The Palestinian issue will be there when the last echo of artillery falls silent; the disparities of wealth, privilege and liberty will continue their corrosive work. With luck, Saddam Hussein will be gone and Iraq no longer will be a menace to the region.

Good and important things can come of this, but they are limited - and they will depend in strong measure on just how the war ends. The end game requires our attention, for it will be the beginning of what comes next. As The Economist concluded recently, "When the war is over, the West cannot impose peace, order and democracy at the point of a gun. That is colonialism, and it doesn't work."