War won't solve everything. It was diplomacy that got us into this, and diplomacy that must ultimately get us out. Until now, the focus of the American government has been on prosecuting the war and keeping the allied coalition together. This is as it should be, but there is no time to lose in beginning to plan for what happens after hostilities cease. Winning the peace may prove tougher than winning the war. What will bring stability to this region?

Although Iraq's ability to make war would surely be broken for years to come, few other Mideast problems would be swept away by military victory. American might and prestige in the Mideast would be at an all-time high, but there's the attendant risk that anti-American feeling might swell.America must assume the role of healer - militarily, economically and politically. We must see to it that new security arrangements protect all nations in the region from future aggression. We must rebuild the war-shattered countries. We must find a solution to the Palestinian problem.

And, as the world's defender of democracy, we must encourage democracy in feudal sheikdoms such as Kuwait. The alternative is Islamic fundamentalism.

There are delicate tricks to all this. After the war, America must convince the world that there will be, if not a Pax Americana, at least a peace fostered by the United States.

Iraq should be required to pay reparations to Kuwait, and an investigation of Iraq's violations of the Geneva Convention should be conducted. Those rules have long been honored by civilized nations. There could be war crimes trials like the Nuremberg trials of Hitler's top commanders after World War II.

Already, Saddam Hussein has sent missiles into civilian areas of Israel - strikes with no military purpose against a non-combatant country. He has paraded captured American fliers before TV cameras in violation of the Geneva Convention. The world hopes Saddam will not resort to chemical weapons . . . but if he does, these barbaric deeds would be a central part of the war crimes indictment. Add the gassing of the Kurds.

The most difficult question of the post-war world will remain the Palestinians. But if real security can be provided to all Mideast countries, perhaps then Israel's reluctance to discuss a Palestinian solution will also abate.