One way or the other, sooner or later, this wretched business with Saddam Hussein will be resolved. It may prove catastrophic; or it may prove merely scary, costly and infinitely messy. But no emergency rolls on indefinitely, and once the grim chapter of Kuwait is closed, what then? Almost regardless of how things evolve, a few giant priorities will demand attention.

Assume for this discussion that Iraq has been made to disgorge Kuwait, that the United Nations coalition has managed to stay together and that Israel remains intact. Assume, too, that any combat, however costly, has managed to avoid unleashing nuclear or chemical weapons. Saddam Hussein, if still in power, sues for peace. Where do we go from there?A first task would be to build on the remarkable United Nations commitment, which has lent this expedition such authority, and commission an international unit that would supervise the truce. Besides helping to cope with the inevitable hordes of refugees, a U.N. security force would be needed to patrol borders and head off flare-ups of hostilities. Such a force might have to remain in place for five, 10 or even 20 years, perhaps acting as the gulf's own policeman along several borders besides that between Iraq and Saudi Arabia. Costs would have to be shared by the oil states themselves.

This arrangement, while onerous and expensive, could become the core of a post-Kuwait structure of stability across the Middle East. It would offer and even impose a rudimentary international peace force that would offer security guarantees, begin to supplement local armies and press for phasedowns of their outlandish stocks of weaponry. Far-fetched? Not if crisis-shocked nations come to realize the folly of wasting their oil billions on war machines, and opt instead for protection under the U.N. umbrella.

Even if war should come, the solidity of the U.N. votes represents something new and highly encouraging in the evolution of the world organization. Created with a vision of keeping the peace, its key members have found the stomach to stand firm on a hard question of unassailable principle. Unless the coalition should crack, in which event all bets would be off, the U.N. should emerge from this showdown as a more believable and more respected voice of authority.

Properly exploited, this enhanced U.N. role could have tremendously positive consequences. By demonstrating an unshakeable seriousness of purpose in thwarting aggression and insisting on peace, the U.N. could attract wider support, political and financial. This, in turn, would make it possible to create a standing U.N. reserve force, such as that advocated at times by both the United States and the Soviet Union.

An equally critical task, clearly, will be for Moscow and Washington to tend whatever wounds this crisis may have inflicted on their warming relationship. Last week, as Persian Gulf anxieties mounted, it was unnerving to learn that Mikhail Gorbachev had ordered Soviet troops to Vilnius to tame the restive Lithuanian population. But it was modestly reassuring, a day later, when word came that Gorbachev had telephoned President Bush and that the two had had what was reported as a positive talk.

Even with the Iraq crisis at some kind of ominous brink, and even considering the frightening implications for the Middle East, nothing in world politics can match for importance the relationship between the United States and the USSR. If it sours once more, then almost everything goes bad. By contrast, if this link can be sustained, and if the Soviet peoples can struggle through their own present nightmare to some new and brighter political future, it could kindle new hopes for international progress.

For America, any aftermath of the Iraqi crisis will force the public and its political leaders to face many hard choices that they have been all too glad to put off. It will be a time for leaner and tighter, a time for finally facing the costs of a decade of greed and squandering. It will be a time, finally, for more saving and investment; a time for Washington to insist, with U.S. labor unions and stubborn West European farmers alike, on a resumption of talks toward freer world trade. In Washington, where the soaring costs of government are driving everyone nuts, it will be a time for finally coming to grips with such things as bloated bureaucracies and America's outsized costs of medical care.

Clearly, this short list only scratches the surface. But whatever the fates have in store for the combatants arrayed in and around Iraq, there will be a time when this dark passage will have been traversed. Now is none too soon to envision how this future might be addressed.