In the wake of U.S. withdrawal from Lebanon three years ago, Secretary of Defense Weinberger and Secretary of State Shultz engaged in an informal debate designed to identify the criteria that should be met before American forces are committed to combat.

Like most Washington debates, this one produced no clear winner. However, on at least three points, a consensus did emerge. Both secretaries appeared to agree that American military involvement could be justified and be successful only if: 1) our goals were clear; 2) the relationship between those goals and our military commitment was understood; 3) those goals and the level of military risk were supported by Congress and the country.

Despite that agreement, both secretaries -- and the president they serve -- are operating in ways that will prevent them from meeting their objectives in the Persian Gulf. They have identified our goals -- and I believe they are goals which all Americans can share and support. Our "escort service" is designed to protect the freedom of the seas, preserve the free flow of oil, and prevent Soviet advances in the area. But they have not been able to spell out how we will react if the level of force we plan to commit cannot achieve those goals.

They have not answered the questions we should have asked back in 1964, when we supported what we thought were reasonable goals in yet another gulf: How far are we willing to go to achieve those goals? What is the relationship between the benefits we expect to achieve and the price we may have to bear? Surely we have learned enough to know that goals are meaningless unless the consequences, both short- and long-term, are considered. Yet, the administration has set limits on our discussion that prevent us from considering this.

While no one disputes that risks exist in our reflagging policy, the discussion of those risks has been limited by the administration's refusal to acknowledge a "risk of imminent hostilities" -- the term of art which triggers the War Powers Act and requires congressional approval of continued deployment of American forces. That refusal means the real commitment we are undertaking cannot be calculated or even considered. Unless Congress takes some action to force a real debate, the president's reflagging proposal will go into effect by default in early July. The country will find itself expanding its role in another gulf without obtaining a national consensus for such an action.

I do not necessarily support efforts to prevent reflagging; I do support efforts to make sure that we understand what we are doing before we do it. While I believe the president's motives may be suspect; while I believe the president has not done enough to secure more than rhetorical cooperation from our allies; while I am concerned by the unwillingness of the Gulf States to give full support to our efforts -- still, I recognize that the president has made a commitment. If we abandon that commitment prematurely, our already shaky credibility in the region will be shattered.

No one wants to abandon the Persian Gulf. But no one should want to be sucked into widening hostilities without a realistic analysis of the threats we face and what it may cost. The only thing worse than walking away from that region now would be to walk into it without fully considering the consequences of our actions. The War Powers Act would require us to consider those consequences.

By triggering the War Powers Act -- and requiring the president to have specific congressional approval for continuing U.S. commitment -- we will create conditions that will force the administration to give Congress and the country an analysis of the possible ramifications of its policy in the Gulf. They will no longer be able to avoid that issue by hiding behind a denial that imminent hostilities are possible. Once we dispose of that fiction, and once cost considerations are on the table, the War Powers Act will allow Congress and the country to give the president a clear and definitive statement about the nation's willingness to take the risks associated with entering that war zone.

No one disputes the desirability of achieving our goals in the region if they can be achieved simply by sending additional ships into the Gulf. But we need to know if those same goals are as desirable if the cost of securing them is the loss of more American lives and an increased probability of an armed conflict with Iran.

In addition, we need to consider whether those goals can be achieved if the war expands: Would the Gulf States really see an American retaliatory attack on Iran as a stabilizing force in the region? Would Soviet influence really be reduced if Islamic factions throughout the region perceived American defensive action as empirical evidence of "Satanic" motives? Will American security interests be promoted if Iran responds to our involvement by launching terrorist attacks on American interests throughout the world?

Those are real questions. They need to be answered -- but they cannot even be asked as long as the administration continues to pursue the fiction that hostilities are not imminent and that the War Powers Act need not be invoked.

I first came to Congress in January 1965, two months after the Gulf of Tonkin Resolution was adopted. Congress accepted, almost without question, the claim that if we just showed some resolve, we would quickly "win" in Vietnam. Ten years later, we were still told the same things. The War Powers Act in 1973 was our response to that disastrous chapter in our history.

The nation certainly learned a lesson from Vietnam; Weinberger and Shultz seemed to have learned a lesson from Lebanon; now we need to apply those lessons in the Persian Gulf. We need to use the War Powers Act to force us to evaluate this policy and require us to build a consensus.

The writer is a Democratic senator from Washington