Israel says there is one sure thing amid the uncertainties over how the U.S.-Iraq showdown will play out: if attacked by Iraq, the Jewish state will respond.

The Palestinians fear Israel might also exploit the turmoil of war for a punishing strike against them, such as expelling their leader, Yasser Arafat.

Both sides agree there won't be a replay of the 1991 Gulf War.

Israel says it is far better prepared for an Iraqi attack, including with chemical or biological weapons, than in 1991, when it was hit by 39 Iraqi Scud missiles with conventional warheads. At the time, under stern U.S. pressure, Israel did not retaliate.

Israel now has the Arrow, a sophisticated anti-missile system, and its own spy satellite, the Ofek. Air force squadrons have intensified training, reportedly including delivery of a nuclear counterstrike to an Iraqi "dirty bomb."

Most Israeli civilians have been given gas masks. Health workers are being inoculated against smallpox. A standard feature in homes and apartments built in the last decade is a "safe room" with metal doors that can easily be sealed to keep out poisons.

"The people of Israel are the most protected in the world against chemical or biological attack," said Transport Minister Ephraim Sneh, a former general.

A U.S. attack on Iraq is widely seen as inevitable, and so is an Iraqi strike against Israel, but military analysts disagree on whether Saddam would use conventional or non-conventional weapons.

Shlomo Aronson, a political scientist at Hebrew University in Jerusalem, said Saddam never used chemical weapons outside his own territory, though he once employed them against invading Iranian troops. "It shows that he is very conscious of the limited use of non-conventional weapons," Aronson said.

However, Amatzia Baram, an Iraq watcher at Haifa University, said the stakes were higher for the Iraqi leader now because the goal is ousting him, not just subduing him.

"When (U.S.) troops are in and around Baghdad, he (Saddam) has no choice. He knows he is doomed and then has to push the button," Baram said.

Israel says that this time, it will strike back.

"What I told the Americans, and I repeat it: `Don't expect us to continue to live with the process of restraint," Defense Minister Binyamin Ben-Eliezer said last week. "If they hit us, we reserve the right of response."

While Israel promises to coordinate with the Americans, it may not be swayed this time to hold back. During the Gulf War, the United States, trying to preserve the Arab coalition against Saddam, insisted that Israel not strike back.

Former Israeli Defense Minister Moshe Arens revealed this month that in 1991, Israeli commandos were training for a ground raid to destroy missile launchers in western Iraq. The war ended abruptly, before the mission could be carried out, Arens wrote.

Israeli officials refuse to talk about the nature of Israel's response, but the expectation is that the payback would be in kind.

Military analyst Zeev Schiff wrote in the Haaretz daily that while the probability of an Israeli nuclear counterstrike is extremely low, it's one of the scenarios in extensive Israeli air force maneuvers.

Israel has reportedly asked Washington for advance warning of a U.S. attack on Iraq. It also requested that at the start of the war, U.S. troops focus on destroying missile launchers in western Iraq, the only area from which the rockets can reach Israel.

It is not clear how many missiles Saddam still has, with estimates ranging from about 20 to several dozen. Iraq also has chemical and biological weapons, and Israel says it has new evidence that production is being accelerated.

Despite the dangers to Israel, 57 percent of Israelis believe a U.S. attack on Iraq is a good idea, according to a recent survey.

Raanan Gissin, an adviser to Prime Minister Ariel Sharon, said that a delay "will only give him (Saddam) more of an opportunity to accelerate his program of weapons of mass destruction."

The Palestinians, who backed Iraq in the Gulf War, said they oppose any attack on Iraq.

There are widespread sympathies for Iraq in the West Bank and Gaza Strip, where Saddam is seen as one of the Palestinians' staunchest defenders in the Arab world. Iraq pays $25,000 to the family of each Palestinian suicide bomber who strikes Israel and has given lower stipends to others killed and wounded in the conflict with Israel.

Arafat today does not openly side with Iraq, after his 1991 alliance with Saddam against Kuwait led to the expulsion of thousands of Palestinians from Gulf countries.

The Palestinian Authority, which is barely functioning, says it doesn't have the means to prepare for the event that an Iraqi attack on Israel, especially with non-conventional weapons, inadvertently hits Palestinian areas.

"We can't distribute medical injections for children in the Palestinian areas, so how can we prepare for any new developments?" said Palestinian Labor Minister Ghassan Khatib.

Since June, Israeli troops have been occupying most West Bank towns to try to prevent terror attacks on Israeli civilians.

Gissin was evasive when asked whether Israel would provide gas masks and other protective gear to Palestinians, should troops still be occupying West Bank towns during a U.S.-Iraq war. "When we reach that stage, we will find a solution," Gissin said.

In 1991, Israel clamped a curfew on Palestinians in all of the West Bank and Gaza Strip for the seven weeks of the Gulf War but did not give them gas masks.

Many Palestinians fear that this time around, Israel would exploit the tumult of a war, with the world's attention turned elsewhere, to carry out a punishing strike against them.

Khatib said the Palestinian Authority is worried that Israel "may dare to do things that the world had prevented it from doing until now," such as expelling Arafat.

Gissin would only say that Israel wants to bring an end to terror attacks, but that "we have no war with the Palestinian people."