Jerusalem ? Israel’s aggressive moves Wednesday toward a war footing with Palestinians generated friction with its closest ally, the United States.

Secretary of State Colin Powell and Prime Minister Ariel Sharon traded harsh words a day after Israel announced it would arm tens of thousands of its citizens to guard against suicide bombers, who have recently attacked buses, bachelorette parties and bar mitvahs. Israeli security agencies have moved to high alert, with guards posted in supermarkets and hotels, gas stations, malls and swimming pools.

Palestinian police officers, fearing a second attack, run shortly after Israeli helicopters hit the Palestinian National Security Center in the West Bank town of Ramallah. No injuries were reported in the Wednesday attack.

The Ma’ariv newspaper stated what was becoming more and more obvious: “The government doesn’t have to declare war,” it wrote. “It’s already here at home.”

Powell was asked in Congress about remarks by Sharon that the Palestinians “must be hit and it must be very painful. We must cause them losses victims so that they feel the heavy price.”

Powell challenged Sharon’s approach in the strongest criticism yet by the Bush administration. “If you declare war against the Palestinians and think you can solve the problem by seeing how many Palestinians can be killed I don’t know if that leads you anywhere,” he told a House of Representatives committee. Sharon, he said, “has to take a hard look at his policies.”

Sharon promptly defended himself, saying in a statement, “The war that Israel finds itself in was forced on it by the Palestinian Authority and its Chairman following the Camp David summit in July 2000. Israel never declared war on the Palestinians; Israel is returning fire against the terrorist organizations in the framework of its right to self-defense.”

Powell also chastised Palestinian leader Yasser Arafat for not doing enough to stop the violence.

A year after taking office, Ariel Sharon was no closer Wednesday to bringing peace to his people than when he became Israeli prime minister.

In the last week the deadliest since the Palestinian intifada, or uprising, began nearly 18 months ago the spiraling tit-for-tat seemed nearly routine.

On Wednesday, Israeli forces divided the Gaza strip into three pieces, attacking Palestinian targets by boat, helicopter and tank. At least a dozen Palestinians were killed, as were two Israeli soldiers.

The invasion followed Tuesday night’s rocket attack into Israeli territory. Two homemade rockets, fired from Gaza, landed in the town of Sderot, injuring two children.

On Sunday a Palestinian sniper picked off 10 Israelis at a checkpoint.

A previously unknown Jewish group claimed credit Tuesday for a schoolyard blast that injured eight Israeli Arabs in Jerusalem, including seven students.

In the West Bank city of Ramallah, the Voice of Love and Peace radio station now plays martial music during the funerals of martyrs. These days, there have been many.

Palestinian Cabinet minister Saeb Erekat had to cancel his talk about prospects for peace; extremists threatened to disrupt his talk Wednesday at Hebrew University. “His security services received a warning that there would be a threat to his life,” said Dr. Oded Eran, a conference organizer.

Sharon popularity waning

It may be difficult to hear such messages when Palestinian leaders such as Marwan Barghouti are calling for attacks on every Israeli army roadblock on the West Bank and Gaza. Barghouti, the West Bank leader of the Tanzim militia, the largest in Yasser Arafat’s Fatah organization, said this at a funeral Tuesday for the family of a militant who was killed by an errant Israeli tank shell. Later that night, the Israelis assassinated Barghouti’s head of operations, whom it blamed for the murder of eight Israelis.

Polls show people are moving from the center to the far ends of the political spectrum. In Israel, Sharon’s popularity has sunk for the first time below 50 percent, while hard-liner Benjamin Netanyahu is gaining. Among Palestinians, support is soaring for Fatah, whose militia has taken credit for a series of recent attacks.

“The public here is extremely supportive of the continuing of intifada,” said

Ghassan Khatib, head of JMCC, a Palestinian research center. “Whoever plays more the prominent role in the struggle and resistance gets more popular.”

Labor Party threatens exit

People on the streets in Jerusalem eye one another warily. A backpack or bulging pockets attract appraising eyes. Palestinians routinely are pulled over and questioned, their papers demanded.

Voices on all sides are growing more hoarse and strident. The Labor Party is threatening to leave the government, which it criticized for warmongering. The right accuses Sharon of being too soft. “There is no alternative to unsheathing the sword of war in order to hasten peace,” the hawkish newspaper Hatzofeh wrote in an editorial Wednesday.

Ze’ev Schiff, a politically moderate military correspondent for Ha’aretz, suggested Tuesday that it might be time to hurt terrorists’ families.

Even Shimon Peres, the peace-minded Israeli foreign minister, sees a need to separate the Palestinian and Israeli peoples.

“We have to make a decision right away for the sake of Israel,” he said. “I see our map. I see our calendar. We cannot keep our majority without a partitioning of the land.”

Appearing before the foreign news media, the 78-year-old winner of the Nobel Peace Prize sounded weary. “We are in an extremely grave situation,” he said. ” . . . Too much blood. Too many victims. Too much desperation. All of us have to try to look for a way out.”