How many times has the world observed an Israeli-Palestinian handshake and breathed a sigh of relief that hostilities in that sliver of the Middle East finally appeared to be ending? The answer, of course, is far too often for the latest declaration of peace to promise much. Camp David, the Rose Garden, Oslo, Sharm el-Sheikh Round 1: All those meetings and accords came and went, and still the blood flowed -- if anything, more copiously. And yet there are signs that this week's truce, also reached at the Egyptian Red Sea resort of Sharm el-Sheikh, just might be the one that holds. Now comes the hard part.

A history of disappointment is not the only reason the rejoicing over this summit seems muted and the expressions of hope so cautious. As observers emphasized Tuesday, what came out of Sharm el-Sheikh was a security accord, not a peace accord; a simple truce, not the complex blueprint required for a permanent reconciliation. Both sides pledged to halt attacks, no more, no less. After more than four years of murderous violence in which there has never been a bilateral ceasefire, that is a huge step. But it is very much a first step.

Still to be addressed are the differences that triggered hostilities in the first place, including such fraught issues as the status of Jerusalem, the so-called right of return for Palestinian refugees, the Israeli-built security barrier and the future of Israeli settlements in the West Bank. There is also a potential stumbling block in disagreements over which Palestinian prisoners Israel is willing to release, when and how many.