The first object of war is to weaken or break the will of the enemy. In the Gulf today, that effort is in full swing. It is a time of temptation and of testing.

For Americans, the challenge is to persuade Saddam Hussein that he cannot succeed in the effort to annex Kuwait and that if he persists in trying, there will be devastating consequences for him and his regime.

To get that message through, the United States must communicate by words and deeds that it is prepared -- indeed has decided -- to use the large military forces now assembled in the Mideast. Any apparent wavering in purpose, any seeming uncertainty, any expressed anxiety undermines the effort. When Saddam Hussein actually believes he has only two options, to withdraw or face war, he may unconditionally withdraw from Kuwait.

For Saddam Hussein to succeed, he must disarm adversaries against whom he is no match militarily. He must break the determination of key players now arranged against him and especially he must break the will of the U.S. government. After all, it was George Bush's will to confront Iraq's aggression that, more than anything, was responsible for assembling the forces now arrayed in the region.

Saddam Hussein has already made various efforts to frighten his adversaries with talks of Jihad (holy war), threats of terrorism and predictions of heavy casualties. He has worked to split the heterogeneous anti-Iraq coalition, accusing the Saudis of defiling Muslim holy places, charging Morocco as a Zionist agent, seeking to inflame the Palestinian issue.

Now comes the peace offensive, launched and denied through emissaries who it is said did and did not communicate in various capitals with various persons, including at least Jordan's King Hussein, Italy's Prime Minister Giulio Andreotti and the Soviet Union's Yevgeny Primakov.

The new hints of an interest in peace came just two days after the Iraqi minister of information had said there was "no room for any compromise." It came one day after The New York Times published a series of interviews with Jordan's Hussein, who warned that war would be catastrophic for the region and for all its participants, and who said he regretted the failure of Bush and other Western and Middle Eastern leaders to respond to earlier signals from Iraq.

The half offer consisted of a half suggestion that a diplomatic solution, a compromise, might be available. Iraq would withdraw from Kuwait and retain only the strategic island of Bubiyan, an oil field at the Iraq-Kuwait border and a few special privileges.

Secretary of State James Baker was right to firmly reject what he called "the siren song" of appeasement. "It's our position that he should not in any way be rewarded for his aggression," he added.

Obviously, Baker understood that Saddam Hussein had begun a new offensive -- this time against the American will and capacity to act. Presumably, Baker also understands that there is no better way for an adversary to prevent the United States and its allies from using their superior force than to hold out the prospect of a diplomatic solution based on a compromise.

If Saddam Hussein does not understand how vulnerable the West is to appeals to peace, his good friend Yasser Arafat does. Words like negotiated settlement, peaceful solution and compromise are the political equivalent of the rubber hammers with which physicians test our reflexes.

It will be very important to remember that, in this context, a compromise would give Iraq part of Kuwait, would reward aggression and would assuredly leave Saddam Hussein stronger than he ever has been. That kind of compromise would embolden him to target next the moderate governments of the region.

Clausewitz tells us that as long as an aggressive man remains armed, he can be persuaded to abandon his aggression by "one single motive alone, which is, that he waits for a more favorable moment for action. . . . If the one has an interest in acting, then the other must have an interest in waiting."

Seeing the forces arrayed against him, Saddam Hussein may now have developed an interest in waiting. In that case, it is more important than ever that the United States and its allies communicate their interest in acting.