As Israel braces for possible war with Iran and its proxies, a new kind of conflict in which the civilian population will be a primary target for massive missile barrages, there are growing concerns about the military's ability to shield cities as well as its key bases.

In the 34-day 2006 war Israel fought with Hezbollah of Lebanon, Tehran's main surrogate in the Levant, the Shiite movement fired some 4,000 rockets, supplied by Iran and Syria, into Israel as far south as the port city of Haifa, at a rate of around 150 per day.

That was the deepest Hezbollah had ever penetrated into the Jewish state. It was a wake-up call for Israelis that in future their enemies could target the whole country.

Amos Harel, defense correspondent of the daily Haaretz, noted a few days ago that Israel's leaders understood that "the enemy … will continue to view the Israeli civilian population as the central weak point and it is there that it will focus most of its attacks."

In 2006, Hezbollah possessed an estimated 12,000 rockets of various calibers, most of them of limited range and destructive power. Last weekend, Israeli Defense Minister Ehud Barak warned that Hezbollah now has some 45,000 rockets and missiles, thousands more than previously estimated and enough to sustain daily fire for months.

According to military analysts, some of those weapons are capable of hitting Tel Aviv, Israel's largest metropolis, the industrial heartland in the center of the country and as far south as the Dimona nuclear reactor in the Negev Desert.

Israel's nightmare is that if hostilities do break out -- most likely if it launches pre-emptive strikes against Iran -- its cities would come under an unprecedented bombardment.

Israel's military said it was positioning its new Iron Dome anti-rocket system along its northern border to counter possible Hezbollah broadsides, instead of the planned deployment in the south against rockets fired by the Palestinian fundamentalists from the Gaza Strip stronghold.

Iron Dome is designed to shoot down short-range rockets, the most perplexing of Israel's military problems because some projectiles are only in the air for around 20 seconds, which makes interception immensely difficult.

The Iron Dome computer can even determine where missiles will land and ignore those that will not hit a town or village.

When Iron Dome completed its test-firings in January, it was hailed as a masterpiece of high-tech Israeli ingenuity that would pulverize Hezbollah and Hamas rockets in the same way that the high-altitude, long-range Arrow-2 missiles would intercept Iran's ballistic weaponry.

But since then critics have claimed that, based on the data released by Rafael Advanced Weapons Systems, which developed Iron Dome, it needs at least 30 seconds to respond to a missile that may only be in the air for 15 seconds.

The third tier of the planned multi-layered missile shield, a system known as David's Sling, to counter medium-range missiles, is still being developed by Rafael and may not be ready for another two years.

On top of that, Arrow-2, built by Israel Aerospace Industries and largely funded by the United States, has never been tested in combat.

So Israelis are realizing that their much-vaunted defense shield is incomplete and that the next war will expose the civilian population to greater risk than ever before. Nationwide deployment of Iron Dome will cost an estimated $1 billion.

With the whole country exposed for the first time, casualties are expected to be high. One estimate puts potential fatalities at 8,000, mostly civilians -- an unprecedented death toll for the Jewish state.

Analysts say that in the event of a coordinated attack by Iran, Hezbollah and Hamas, and possibly Syria, the Israeli air force, the most powerful in the region, would be overwhelmed and not be able to knock out every missile launch site.

Israeli commanders have said as much publicly, indicating they seek to prepare the civilian population for the worst.

According to Haaretz's Harel, the military plans to deploy the first two -- and so far only -- Iron Dome batteries "on its bases, and is in no hurry to deploy them in the most threatened southern cities, Sderot and Ashkelon."

Overall, Iron Dome is "no silver bullet," concluded Yiftah Shapir of the Institute for National Security Studies. "In fact it's not going to solve any of our problems."