OCCUPIED JERUSALEM: Despite its confident saber-rattling, Israel's concern is growing that the country is vulnerable to a devastating counterstrike if it attacks Iran's nuclear program.

An announcement this week that a mobile rocket-defense system will soon be built just outside Tel Aviv, where Israel's sprawling military headquarters sits smack in the middle of office towers, museums, night spots and hotels, caused some jitters. Israeli officials cite intelligence reports that Tel Aviv would be a main target of any attack.

Increasingly, the debate in Israel is turning to whether a strike can do enough damage to the Iranian program to be worth the risks. Experts believe that any attack would at best set back, but not cripple, the Iranians.

Skepticism about Israel's ability to defend itself runs deep here. Israelis still remember Iraqi Scuds landing in the center of the country 20 years ago. In 2006, the Lebanese Hezbollah militia seemed able to rain rockets at will during a monthlong conflict with the Jewish state. A scathing government report issued months ago suggested the homefront is still woefully unprepared.

In a questionably timed move, the Cabinet minister in charge of civil defense in recent days resigned to become the ambassador to faraway China.

Vice Prime Minister Dan Meridor, who also serves as minister of intelligence and atomic energy, indicated Monday that Israel was facing a new type of peril.

"Whereas in the past, there was a battlefield where tanks fought tanks, planes fought planes, there was a certain push not to see the homefront affected. Now the war is mainly in the homefront," the normally tight-lipped Meridor told The Associated Press.

"The whole of Israel (is vulnerable to) tens of thousands of missiles and rockets from neighboring countries. So of course we need to understand the change of paradigm," he continued. "If there is a war, and I hope there isn't a war, they are not just going to hit Israeli soldiers. The main aim is at civilian populations."

Both Israel and the West believe Iran is trying to develop a nuclear bomb - a charge Tehran denies. Israel believes a nuclear-armed Iran would be a threat to its very existence, citing Iranian leaders' calls for its destruction.

Israel has welcomed international sanctions imposed on the Islamic regime, but it has pointedly refused to rule out military action. In recent weeks, top leaders have sent signals that patience is running thin.

An Israeli military strike would very likely draw an Iranian retaliation, experts believe, which would involve either Iran firing its long-range Shahab missiles or acting via local proxies of Hezbollah in Lebanon, Hamas in Gaza or even Assad loyalists in Syria.

Experts believe the experience of the 2006 war against Hezbollah, in which the guerrillas rained 4,000 rockets onto Israel, is just a small taste of what could lie ahead. The chief of military intelligence recently said that Israel's enemies now have some 200,000 rockets and missiles aimed at Israel.

But this time, Israel's main population centers are believed to be possible targets. In the past, rockets fired from Gaza or Lebanon have been directed at smaller, marginal communities, the largest being regional centers like Haifa in the north or Beersheba in the south.

Leaders believe that Israel's main cities would be targeted by more sophisticated, longer-range missiles.

Jerusalem is considered relatively safe because of its Islamic holy sites. But the Mediterranean coast, home to most of the country's population, with Tel Aviv as the gleaming target at its center, seems like a very attractive target.

The business and cultural capital of the country, with a metropolitan population of over 2 million, Tel Aviv is critical to Israel's image of itself as a modern place with a Western lifestyle. Israel happily markets the city as a high-tech, fun-loving hub.

Aside from a spate of Saddam Hussein's rudimentary Scud missiles in 1991, the city has never truly been tested before. Although the Scuds caused little damage memories of that war are vivid; the strikes caused widespread panic and tens of thousands of people fled to safer areas of the country or left altogether.

A prolonged siege on the city today could likely fuel another exodus.

Israeli defense officials warn that Syria, a close Iranian ally, is believed to possess GPS-guided missiles and chemical weapons. Hezbollah has greatly improved its arsenal since the war, and militants in the Gaza Strip, to Israel's south, are believed to be smuggling powerful warheads from Libya.

The officials, speaking on condition of anonymity because they were discussing a sensitive security matter, said intelligence reports indicate that Tel Aviv military headquarters will be targeted and an alternative site for military headquarters is being prepared.

Defense Minister Ehud Barak has estimated that an Iranian attack would claim fewer than 500 Israeli casualties - a statement intended to calm the nation, but which has achieved the opposite effect.

The concerns for the homefront have dovetailed with fears around the world that an attack could unhinge the global economy and spur terrorist attacks against the West.

For the past five years, Matan Vilnai - a veteran Cabinet minister and one-time deputy military chief of staff - has been responsible for preparing such scenarios. Vilnai recently announced he was stepping down, leaving for China as Israel's new envoy.

On Sunday, he gave Cabinet a progress report on homefront preparations. His comments were not made available to the public and Vilnai did not respond to requests for an interview by The Associated Press. But Israeli media quoted the former general as being outraged at insinuations that he was "running away."

Prime Minister Benjamin Netanyahu acknowledged after Vilnai's presentation that more work must be done in "an era of threats to the Israeli homefront."

Israel's performance in the 2006 war was widely seen as a disaster, particularly because of the military's inability to stop the barrage of Hezbollah rockets on northern Israel. The country's military chief and defense minister at the time were forced to resign; a government report found "serious failings and flaws" by politicians and the military.

Five and a half years later, Israeli air defenses are vastly improved.

Its multilayered shield includes the "Iron Dome" defense system, which shoots down rockets fired from short distances, the "Magic Wand," aimed at stopping intermediate-range missiles, and the "Arrow" missile defense system meant to protect Israel from Iran's expanding array of missiles.

The Iron Dome has already proven effective in knocking down Palestinian rockets from the Gaza Strip. But only three Iron Dome batteries have been deployed, while expert say 14 are needed to cover the country.

The system is expected to be deployed in central Israel for the first time in the coming days. The military insists the timing is part of an annual training plan for the system, but the deployment in the nation's heartland has added to fears that Israel was approaching a threat it has never encountered before.

The Arrow, built by state-run Israel Aerospace Industries Ltd. and Chicago-based Boeing Co. for more than $1 billion, has been designed specifically to intercept Iran's Shahab ballistic missile, which is capable of carrying a nuclear warhead and whose range of 1,250 miles (2,000 kilometers) easily covers all of Israel. The Arrow has not yet been tested in combat.

There are signs that budget cuts threaten some preparations.

A report in December by the State Comptroller, the government's internal watchdog agency, found local authorities failed to properly conduct homefront emergency drills and that hundreds of thousands of Israelis did not have functioning gas masks or a designated bomb shelter. The government pledged two decades ago to distribute gas masks nationwide.

The military would not confirm a report that the country's annual national homefront drill had been canceled due to a financial shortfall. "A variety of measures are being assessed in order to avoid harming the operational readiness of the Home Front Command," it said in a statement.

Uzi Rubin, a former director of the Arrow project in Israel's Defense Ministry, said the Israeli homefront is far more organized, coordinated and prepared than it was in 2006.

"Given the circumstances, we are more ready than in the past. But we still need to do so much more," he said.