hile President Bush reworks drafts of a new Mideast plan, his agenda is being yanked from under him by delusional young Palestinians. For the second day in a row, Jerusalem yesterday witnessed the numbing routine of suicide bombing. And for the second day in a row, Mr. Bush's spokesmen said he was forced to delay his speech.

It makes sense for him to wait now, since the impact of the address would be lost amid the funerals, rage and retaliation. But the fact that the president delayed until this month to prepare to act has facilitated the ongoing descent into killing and the mutual infliction of pain.

Prime Minister Ariel Sharon will not solve this crisis on his own, with his policies in the West Bank and Gaza Strip — the building of settlements, the failure to offer Palestinians anything beyond threats and humiliation, the retaking of land. Right now, however, the biggest threat to the Palestinians' national movement comes not from Israel but from within their own society. For months, Palestinians have grown intoxicated with the idea of power through death. They are exalting the most vicious acts of their own young. A poll last month showed that two-thirds believe they have accomplished more through two years of violence than through all the previous years of negotiation.

This is a severe failure of Palestinian leadership. It is very nice that 55 Palestinian intellectuals took out a full-page advertisement yesterday complaining that suicide bombings inside Israel "do not achieve progress toward achieving our . . . freedom and independence." But this is way too little, way too late. Suicide bombing, once limited to the militant groups of Hamas and Islamic Jihad, has become the tool of a group linked directly to Yasir Arafat's Fatah party, the Al Aksa Martyrs Brigades, which has given a sad new meaning to equal opportunity through female suicide bombers.

Each side in this struggle is now locked into a position in which it sees any concession as rewarding the misbehavior of the other. Only the United States can affect this stalemate. Despite the rage on both sides, a majority of both populations continue to believe in two states living side by side in peace. The solution remains clear. Only the leaders seem not to understand it. Mr. Bush needs to announce a timeline of moves required of each side — the abandonment of select settlements by Israel, say, and the imprisonment of terrorist leaders by Palestinians — in order to break this dynamic. And he must do so soon.