Palestinian Authority President Mahmoud Abbas and Hamas leader Khaled Meshal went to Mecca after more than 130 people had been killed, hundreds wounded and a burning sense of urgency had taken over the Palestinian streets. Gazans had been confined to their homes for days, this time not as the result of an Israeli curfew or aerial attack but rather from fear of getting caught in the crossfire. Palestinian society, it seemed, was on the brink of civil war.

The pressure from below had an impact, and within two days Fatah and Hamas leaders, through the mediation of Saudi Arabia's King Abdullah, succeeded in accomplishing what they had not managed to achieve during the preceding year: a unity government. Thousands of Palestinians spontaneously filled the streets of Gaza to celebrate what seemed to be a historic moment.

As I write, the clashes have indeed subsided, but it is unclear whether the calm will persist. On the one hand, the agreement's fine points have yet to be hammered out, and the devil is often in the details. On the other hand, what lies ahead does not depend solely on goodwill between Fatah and Hamas.

Most pundits have understood the sectarian clashes as either a struggle over who will control the Palestinian government and resources or as a local manifestation of a much broader international conflict between fundamentalist and secular forces in the Islamic world. Such interpretations, however, have obscured the central role Israel and the United States have played.

Even before Hamas won the January 2006 democratic elections, after which the Quartet of Middle East mediators (the United States, the European Union, Russia and the United Nations) cut off aid to the Palestinians, Israel's closure of the territories had triggered an economic crisis. More than 60 percent of the Palestinian inhabitants were living under the international poverty line of $2 a day, with the World Bank reporting that 9 percent of children were suffering from acute malnutrition. Considering that the financial aid provided to the Palestinians had amounted to almost one-third of the per capita gross national income in the territories, the imposition of economic sanctions has been catastrophic.

The closure and sanctions have not only wreaked havoc on the Palestinian economy but have also helped precipitate the violent clashes among the factions. Indeed, the idea behind the sanctions, which both Israel and the United States have pressured other countries to enforce, is to shape power relations within Palestinian society by adopting a scheme that, for clarity's sake, one could call the Somalia Plan.

For months now the Palestinian Authority has been unable to pay the salaries of its 160,000 employees. These workers provide the livelihoods of more than 1 million people--almost a third of the population. Some 70,000 work for the numerous security organizations, most of which are linked to political factions. Like those employed by civil institutions, such as the education and health ministries, they are deeply angry because they cannot feed their families. But unlike the civilian workers, they are armed. Under these conditions, it is not surprising that a power struggle has erupted. Inadequate resources, economic sanctions, thousands of armed men in distress and foreign support of certain factions are, after all, the ingredients from which warlordism, à la Somalia, is made. Insofar as this is the case, success of the unity government is contingent on ending the economic sanctions.

But here comes the snag: Israel's unilateralist government is not really interested in a negotiating partner and sees Palestinian unity as a threat. Even before the Palestinian leaders returned home, Israel launched a well-orchestrated diplomatic campaign to persuade the Quartet to uphold sanctions. Simultaneously, Prime Minister Ehud Olmert declared that any future negotiations would be informed by a "three no" approach: no to dividing Jerusalem, no to a withdrawal to the 1967 borders and no to a solution to the Palestinian refugee problem. Thus, Israel is unwilling to discuss any of the contentious issues that need to be resolved.

The unfolding events also set the stage for making the February 19 Jerusalem summit inconsequential. Nonetheless, Secretary of State Condoleezza Rice did make some significant statements during her Middle East visit. It is unlikely that a Palestinian state will be created before President Bush ends his term, she told the Palestinian newspaper Al Ayam. And to the Israeli daily Ha'aretz she added that the Palestinian unity government will not be recognized--suggesting that sanctions would continue--until it abides by Israel's three conditions: that the Palestinian government recognize Israel, renounce violence and ratify the Oslo agreements and the road map. While these demands are in many respects legitimate, they could readily be part of negotiations rather than a weapon used to precipitate internal violence and thus destroy Palestinian society.

Ironically, Israel's position is inimical to its own interests. If the internal Palestinian clashes resume and develop into a full-blown civil war, there will be no hope of resolving the conflict between Israel and the Palestinians. One has to be extremely shortsighted not to see how the absence of a united Palestinian leadership will undermine all efforts to bring about local and regional peace.

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