NO ONE KNOWS when the Persian Gulf war will end -- or how. The nature of the coalition's victory will largely determine the peace that follows. But it's time to start thinking about that peace. The terms of a settlement will influence Iraqis as they try to decide how long they want to keep fighting. They need to see that it will be firm, but not vengeful.

President Bush has said repeatedly that the peace and stability of the region are among the United States's goals. In congressional testimony last week, Secretary of State James A. Baker elaborated some of the administration's ideas. One new and useful element is a proposal for international cooperation to speed up the Middle East's economic development.

Within the Arab world there exist, at close proximity, great extremes of wealth and poverty. Saddam Hussein has been able to draw an enthusiastic response from the streets of a number of Arab cities by representing himself as the champion of the poor, a sort of Robin Hood seizing the riches of Kuwait for the masses. That pose is, of course, entirely disingenuous because Iraq has oil reserves far beyond Kuwait's, and if Iraqis live badly the reason is not a lack of resources but their leader's insistence on expensive weapons and futile wars. But the economic tensions among the Arabs are real and, if there is to be stability after the war, the settlement must address them.

The rich oil-producing states are not capable of defending themselves militarily. For years they got along by paying off the various possible aggressors but, as they learned last August, that kind of protection is unreliable. They also know, or ought to know, that neither the United States nor any other of their allies expects to leave large armies in the Persian Gulf after the war. There may be peacekeeping forces, perhaps under the U.N.'s flag, but the oil states will need more reassurance than that.

How about an international development bank for the Middle East? Mr. Baker said that the United States would be willing to take part, although most of the money ought to come from the oil states. It would be used to push economic growth not only in their own countries but throughout the region. Iraq would take part, both as contributor and beneficiary.

That puts a question to Kuwait, Saudi Arabia and the other wealthy oil producers. Egypt, for example, has an economy that produces less than $700 a year per capita. It has sent well trained and effective troops to fight for the oil states, where incomes are as much as 20 times higher. What do the Kuwaitis, etc., propose to do in return? It's not merely a matter of showing gratitude but of tying the region together in productive economic institutions that no country will have any interest in disturbing.

The United States cannot impose a peace settlement on the Middle East. But it is taking the initiative in outlining the form that a settlement might take. It would now be useful to hear a response from the Middle Eastern countries whose support for these ideas -- or lack of it -- will be decisive.