"The Gaza withdrawal should have been a step toward an Israeli-Palestinian settlement; instead, it could become a leap away from it. The big winner so far is Hamas, which rejects Israel's existence. In Israel, continuing disorder will give a boost to hard-line challengers to Prime Minister Ariel Sharon, the architect of the Gaza evacuation. As it is, Mr. Sharon probably will reiterate in an address to the United Nations today that Israel will consider no more territorial withdrawals or other concessions to the Palestinians until militant groups are dismantled. Unless Palestinian and Egyptian leaders take immediate steps to fulfill their commitments in Gaza, they will bear the responsibility for a new stalemate -- or worse -- in the Middle East."