Jerusalem ? Less than two months after Palestinian militants declared a shaky cease-fire with Israel, raising hopes that both sides finally might be ready to negotiate a peace agreement, the so-called “road map” peace plan strongly backed by President Bush is in shambles.

The increased violence that’s sure to follow will make life more miserable for Israelis and Palestinians, and the perception that the United States and Israel are allied against Arabs and Muslims is likely to help militant and terrorist organizations from Hamas to al-Qaida recruit new members, compound the already difficult American mission in Iraq and complicate the Bush administration’s efforts to remake the Middle East.

The “road map” to peace between Israel and the Palestinians was born more of hope and necessity than of experience. After nearly three years of violence, U.S. officials expected, Israelis and Palestinians would find a three-month respite from bloodshed so addictive that they would find some common ground, take some modest risks and overcome enough of their differences to keep hope alive.

Hope lived just 52 days. Early Thursday, two days after a bus bombing in Jerusalem killed 20 people and injured more than 100, including many children, and with no sign that the Palestinian Authority was prepared to move seriously against the perpetrators, Israel used helicopter-fired missiles to assassinate a Hamas leader.

Hamas and the militant group Islamic Jihad declared their cease-fire over and vowed new attacks on Israel. The moderate Palestinian prime minister, Mahmoud Abbas, is powerless to stop them because Yasser Arafat — still considered the Palestinians’ legitimate leader despite President Bush’s effort to undermine him — refused to support a crackdown.

In response, Israel’s targeted military attacks on Palestinian extremists — missile attacks, nighttime raids — are likely to continue with an intensity unrivaled during the current Palestinian uprising.

A senior Israeli security official said strikes against militants would continue unless the Palestinian Authority eradicated the terrorist threat.

“The formula is quite simple,” the official said, speaking on condition of anonymity. “If they do absolutely 0 percent, we’ll do 100 percent. Where they fail to act, we’re acting.”

The resumption of Palestinian terrorism will make it virtually impossible for the Bush administration, loath to pressure Israel even before the 2004 election year was approaching, to urge restraint on Israeli Prime Minister Ariel Sharon, and it may strengthen the view of some administration officials that Israel and the United States are allied against a common enemy that has many names but common goals.

Many Israelis back the new military tack.

A poll published Friday in the moderate Israeli daily newspaper Yedioth Ahronoth found that 2 in 3 people favored breaking off talks with Abbas and about half favored widespread military strikes against Palestinian extremist groups. The poll of 501 people has an error margin of 4.5 percentage points.

Many Palestinians are equally determined to strike back at Israel. In one of the largest demonstrations since the uprising began, tens of thousands of Gazans chanted “revenge, revenge” Friday at the funeral for slain Hamas leader Ismail Abu Shanab. They demanded that Abbas resign and be cast out of Palestinian territory for being an Israeli and American puppet.

Since Thursday night, Hamas has lobbed mortar shells at Jewish settlements in the Gaza Strip and launched Qassam rockets, at least one of which damaged a home in the southern Israeli town of Sderot.

In response, Israeli forces blocked several Gaza road junctions Friday, dividing the strip of land along the Mediterranean in two and tightening the military hold it had loosened as a goodwill gesture during the early days of the cease-fire. In the West Bank city of Nablus, three militants from the al Aqsa Martyrs’ Brigades, a group affiliated with Arafat’s Fatah political movement, were killed in a gunfight with Israeli troops.

In many respects, the road map and the cease-fire de-clared unilaterally by the Palestinian militant groups died natural deaths, which make their demise no less tragic.

Israel and the Palestinians never saw eye-to-eye, and neither side ever abandoned its belief in an eye for an eye, often with interest. Israel demanded that Abbas’ Palestinian Authority first arrest, dismantle and otherwise defang Islamic militants who had attacked Israel for the past three years. Palestinians demanded that Israel immediately release prisoners and withdraw from Palestinian territory.

Many Palestinians consider attacks on Israel a legitimate tactic of war, and they expected Sharon to respond to even a shaky cease-fire by releasing thousands of Palestinian prisoners in Israeli jails, even those who had Israeli blood on their hands. But Sharon refused to release men convicted of terrorist acts.

Palestinians also expected that during a cease-fire, Israel would stop entering Palestinian territory and conducting raids at will. Those raids resulted in the deaths of militant leaders, whose organizations then launched counterattacks on Israel.

Expansion of Jewish settlements in Palestinian territory also continued, including rebuilding some outposts that the Israeli military had ostentatiously torn down.

Israel “gave the impression that the occupation was being consolidated rather than removed,” said Palestinian Labor Minister Ghassan Khatib. Some West Bank and Gaza roadblocks hampering Palestinian movement were removed, but many others remained, including one that cut off the city of Qalqiliya from the rest of the West Bank.

Perhaps most important, Sharon and Bush never had a credible negotiating partner. On Thursday night, Abbas went hat in hand to ask Arafat to order his militias to destroy extremist groups. Despite heavy-handed U.S. efforts to discredit Arafat and shower international legitimacy on Abbas, the prime minister could never deliver on his assurances to end terrorism.

Now, with Abbas marginalized by Arafat’s continuing grip on power, the cease-fire broken and the Bush administration preoccupied with Iraq and reluctant to invest more pre-election capital in the tattered road map, it’s likely to be the militants of Hamas and Islamic Jihad who decide what happens next.