A dilemma, by definition, is the unavoidable choice between two equally unattractive alternatives. Since Aug. 2, when Iraq invaded Kuwait, President Bush has been impaled on a dilemma's horns. Now he has another tough decision to reach.

The choice on Aug. 2 was clear. Bush was damned if he intervened and damned if he didn't. He chose to send in the 82nd Airborne Division. In the beginning he enjoyed apparent widespread support. To listen to the radio talk shows, that support is slowly eroding. The president's approval rating has fallen under 50 percent. He needs a boost.Once again he faces a hard choice, between calling or not calling Congress back into session.

The risks are evenly balanced. If Bush could be assured that a resolution of firm support for his action would be overwhelmingly adopted, it would be worth the effort. Such a gesture by Congress would carry a strong message to Saddam Hussein in Iraq that American resolve has not wavered. The president's hand would be strengthened. A ringing resolution of congressional approval would encourage our allies in this venture.

The trouble is that the leadership cannot give such assurance. Let us recall a recent piece of dumb-show.

In the House, Rep. Dante Fascell of Florida took the lead in crafting House Joint Resolution 658. It was a long document that began by condemning Iraq's unprovoked aggression and went on to "affirm" the president's five stated objectives and to "support" the deployment of troops in the Persian Gulf region. The resolution concluded by acknowledging that Bush had reported his actions to Congress in compliance with the War Powers Resolution of 1973. On Oct. 1 the House passed HJR 658 by the resounding vote of 380-29.

The Senate, meanwhile, was engaged with its own Concurrent Resolution 147. It was a much shorter document, carrying the uncertain beat of muffled drums. In the Senate version, Congress "strongly approves the leadership of the president in successfully pursuing" the adoption of U.N. resolutions. Congress "approves the actions taken by the president in support of" the five goals. And Congress "supports continued action by the president in accordance with United States constitutional and statutory processes to deter Iraqi aggression and to protect American lives and vital interests in the region." On Oct. 2 the Senate approved its concurrent resolution by a vote of 96-3.

The House sent its resolution to the Senate Foreign Relations Committee. It died there. The Senate sent its resolution to the House Foreign Affairs Committee. It died there. It was an ignominious performance all the way.

If this was the best Congress could do in the first week of October, what could be expected of Congress in the first week of December? The president urgently needs an expression of strong bipartisan support. What he does not need is a tentative, watered-down, milquetoast resolution, adopted by a widely divided vote. An irresolute resolution would be worse than no resolution at all.

Other avenues ought to be explored for providing the moral support that Bush deserves. House and Senate leaders made a helpful gesture by joining the president this week in Saudi Arabia. If major national organizations - veterans groups, labor unions, patriotic societies, professional and trade associations - would adopt well-publicized expressions of support, they could strike a blow against the rising voices of discontent.

Bush is right in what he has done so far. He has stated the five goals clearly and repeatedly: to achieve Saddam's unconditional withdrawal, to restore the legitimate government of Kuwait, to provide for stability in the Persian Gulf, to protect American lives and to move toward a new world order of peace. His policies are to stop aggression, to help our friends and to protect our national self-interest in Middle Eastern oil.

These are sound goals and prudent policies. It is high time for those who support the president to let him know it.