WHAT FRAIL and fast-fading chances remain for a political way out of the Iraq crisis hinge on the several Arab emissaries currently in Baghdad. They apparently bring no new diplomatic twists, but they have one distinction: they are Arabs. All along, the theory of an "Arab solution" has been that since Saddam Hussein insists the matter of Kuwait is exclusively an Arab issue, he might offer Arab mediators concessions he would not consider making to others. By this hopeful and unproven theory, it was no surprise that President Hussein humiliated (making him wait a day for an audience) and then repudiated the mediation of the latest peace petitioner, the secretary general of the United Nations; he dismisses the U.N. as a front for the United States.

Even as the secretary general vainly sought political restraint in Baghdad, American officials solicited military restraint in Jerusalem, attempting to make sure that Israel will not preempt and that, if it does feel compelled to respond to the strike that Iraq has malevolently threatened, it will do so in due proportion. It is a remarkable request the United States is making, one it could not conceivably make without giving an ironclad commitment to respond for Israel if Israel is attacked. Yet it is an essential request, one made to undercut Baghdad's professed intent instantly to "Zionize" the war and split the anti-Saddam coalition. By rejecting Saddam Hussein's demand to be bought out of Kuwait at Israel's expense, Washington earns a most respectful hearing. American-Israeli friendship is being tested as never before.

These last-minute missions are intended to avert and, if that fails, to control the shape of war. But everyone must know there is no predicting the content of unfolding events, the layers of possible outcome and -- to cite the single index necessarily of greatest immediate concern to Americans -- the final toll in human lives.

What can be said at this point is that the American government is going into the countdown having done what it takes to secure unprecedentedly broad international and domestic approval. President Bush has asked for and received the aware consent of most other nations in the world and of most members of both houses of the U.S. Congress. These constitute the basic essential standards for American intervention forged in the fires of the Vietnam War. They lend American policy an important measure of authority as a terrible hour nears.