Remembering its shameful inaction in Rwanda a decade ago, the international community has warned of genocide in Darfur and threatened sanctions against Sudan. Unfortunately, these symbolic steps will not stop the violence in Sudan, and in fact they may exacerbate it.

International condemnation of Sudan is emboldening Darfur's anti-government rebels to reject compromise and escalate their attacks. Confronted by a persistent rebel offensive, Khartoum refuses to rein in its army and allied militia, which are conducting their counterinsurgency by perpetrating genocide.

Even if the United Nations could overcome opposition from Russia and China, sanctions would not compel Khartoum to halt genocidal tactics against the rebels, because its army lacks the means to fight them conventionally. Nor is there international will yet to intervene to stop the violence. The United States is preoccupied in Iraq, and the African Union lacks the logistics and the nerve to invade a sovereign state. The only way to stop the genocide is for the rebels to accept a cease-fire.

But the rebels refuse to halt hostilities, even to allow the delivery of humanitarian aid to civilians on whose behalf they supposedly are fighting, because they are convinced that the international community is on their side. They coldly calculate that the longer they fight and provoke government retaliation against their civilians, the more likely international intervention on their behalf will be.

This phenomenon has been noted even by one of Khartoum's staunchest critics, Pulitzer-Prize winning author Samantha Power, who recently described "a rebel movement emboldened by the belief that the United States is on its side" [op-ed, Sept. 13].

Darfur is not unique. The international community has repeatedly exacerbated ethnic conflict through what I call the "moral hazard of humanitarian intervention." By threatening to intervene against states that use excessive force, we increase the prospects of rebellion and armed secession -- and thereby encourage them.

In Bosnia 10 years ago, the head of U.N. peacekeepers complained that the Muslim-led government, which had armed and seceded from Yugoslavia, was breaking cease-fires because if it "attacked and lost, the resulting images of war and suffering guaranteed support in the West for the 'victim state.' " His predecessor likewise observed that the Muslims were "committed to coercing the international community into intervening militarily." This coercion eventually succeeded, but only after three years of war and 150,000 deaths.

A few years later the scenario played out in Kosovo. Rebels of the Kosovo Liberation Army (KLA) attacked Serbian targets, provoking retaliation against Albanian civilians that succeeded in attracting NATO intervention. A senior rebel later admitted to me: "We knew our attacks would not have any military value. Our goal was not to destroy the Serb military force [but to make it] become more vicious. . . . We thought it was essential to get international support to win the war." Another KLA leader confessed to the BBC: "We knew full well that any armed action we undertook would trigger a ruthless retaliation by Serbs against our people. . . . We knew we were endangering civilian lives, too, a great number of lives."

In Sudan's peace talks, the government has accepted two African Union peace proposals that the rebels have rejected. Khartoum said the union could substantially expand the size of its small peacekeeping force in the country so long as it was dedicated to maintaining a cease-fire by cantoning the rebels. The government also accepted a humanitarian protocol to facilitate aid to the civilians it is accused of targeting for genocide.

But the rebels rejected both these peace proposals, apparently because the compromises would mitigate humanitarian suffering and thereby reduce the likelihood of decisive international intervention. In a remarkably cold calculation, the rebels continue to sacrifice the lives of their own civilians to gain political leverage.

None of this excuses the barbarity of the government. Khartoum has armed the Arab militia troops, given them a green light for wanton violence against black rivals in rebel-held areas, and launched airstrikes -- a campaign that Secretary of State Colin Powell has rightly labeled genocide. The authors of this violence should be apprehended and punished in due course.

But the immediate priority is to stop the killing. If the international community pressures only the government side, while giving the rebels a pass, the war will continue, as will the genocide.

American diplomats should insist the rebels accept the African Union proposal to halt fire and be protected in specified areas by its peacekeepers. If the rebels stopped fighting, Khartoum would lose its excuse not to rein in the militias. If genocide nonetheless continued, even Sudan's defenders in the U.N. Security Council might accept the argument that the time had come for decisive intervention.

The writer is resident assistant professor of international relations at Johns Hopkins University in Bologna, Italy, and author of "The Limits of Humanitarian Intervention: Genocide in Rwanda."