AS HILLARY CLINTON begins her first diplomatic visit to the Middle East today in Egypt, the obstacles to peace in the region are daunting. But Palestinians and Israelis need a two-state peace agreement more desperately than ever. And America's need to forge such a peace is more acute than ever.

If Clinton and the Obama administration's special envoy for the Mideast, George Mitchell, are to succeed at peacemaking, they will have to be patient but tough, aware of complexity but willing to cut through the excuses and sophistry of leaders in both camps.

In Israel, Likud leader Benjamin Netanyahu appears to be in the process of forming a right-wing government. He is opposed to a Palestinian state, determined to maintain Israel's occupation of the West Bank, and unwilling to halt the expansion of settlements there.

Before leaving for the region, Clinton made a good start by passing a message that Israel is not doing enough to allow humanitarian aid to enter Gaza. When she attends a donors' conference for Gaza today in Egypt, Clinton ought to make it clear that America views the ongoing suffering of civilians in Gaza as intolerable. Tens of thousands had their homes destroyed during Israel's assault on the Gaza strip.

Because Israel is restricting the number of trucks entering Gaza, the populace is struggling to survive with too little water, sanitation, and healthcare. Clinton should use her platform in Egypt to call on Israel to allow supplies of building materials into Gaza - so that the $900 million in Gaza reconstruction aid pledged by the United States can have the desired effect. Ideally, Israel should be one of the principal donors of humanitarian assistance to Gaza - to help rebuild what it destroyed, and to correct the impression that Israel seeks to punish the general population of Gaza to obtain favorable terms for a truce with Hamas.

The political situation on the Palestinian side is no brighter than on the Israeli side. Egypt is trying to broker agreement on a unity government betweeen the rival factions Fatah and Hamas. Clinton ought to encourage such an outcome. There can be no serious peace negotiations without a government able to speak for the Palestinian people, and deliver on any agreement.

Achieving the peace that eluded Bill Clinton at Camp David would be an honorable ambition for Hillary Clinton. Few diplomatic achievements would yield bigger benefits for America and its allies. But she is starting out on a rough road. She will have to help construct a regional framework for Israeli-Palestinian peace. She needs to be demanding with allies and shrewder than the spoilers.