Amid a welter of reports about how Israel is upgrading its defenses to counter long-range Iranian missiles, military commanders say the gravest threat comes from closer to home: Hezbollah's reputed arsenal of 43,000 missiles and rockets.

The answer: Rafael Advanced Defense System's combat-proven Iron Dome system and the David's Sling weapon that's being fast-tracked through development, largely because of U.S. funding.

The Haaretz daily reported Monday that the military command has assessed that in the event of a new war it would be able to cope with ballistic missiles from Iran or short-range rockets fired by Palestinian militants in the Hamas-ruled Gaza Strip.

It quoted a senior military officer as saying" the major problem Israel faces is the significant missile arsenal Hezbollah has and its ability to fire rockets at Israel for a long period of time.

"Hezbollah is the long arm of Iran ... This terrorist organization will undoubtedly barrage Israel with thousands of missiles ... Hezbollah can cover Israel with rockets," the officer was quoted as saying.

Hezbollah can fire more than 200 missiles a day at Israeli cities for weeks on end if need be. The number of Iranian ballistic missiles involved would be much smaller, although they carry more destructive warheads.

Most of Hezbollah's rockets are believed to be short-range weapons that can reach northern Israel. But it's also reported to have hundreds of long-range guided missiles capable of hitting anywhere in the Jewish state.

Hezbollah's current arsenal is almost four times the number of rockets it had in July 2006 when war broke out with Israel. During that 34-day conflict, Hezbollah fired around 4,000 missiles into the Galilee region, including the port city of Haifa.

That was the first time since Israel was founded in 1948 that it had been subjected to such a bombardment that targeted population centers, a development that spurred Israel's drive to build up its defenses.

In recent weeks, the Israelis have made much of upgrades for the high-altitude, long-range Arrow 2 missile that is the main defense against Iranian and Syrian ballistic missiles.

But the Iron Dome, designed to counter tactical rockets and missiles with a range of 2.5 to 40 miles has been given little attention as Israel's military braces for conflict with Iran.

But it too has been upgraded and is now capable of firing radar-guided Tamir interceptor missiles with extended range to combat Palestinian rockets whose range is steadily increasing, threatening Tel Aviv.

Iron Dome, the only system in the world able to combat short-range projectiles in the air for only a couple of minutes, got its baptism of fire in early 2011 against Palestinian rocket barrages.

It's been in action periodically since then.

The system's computer is able to project which incoming rockets will hit populated areas and concentrate on them, ignored those headed for unpopulated zones.

It's intercepted more than 90 Russian-designed Grad rockets and Hamas-built Qassem rockets since its first interception in April 2011.

It's notched up a kill rate of around 75 percent of those rockets it engaged. Military sources say that's expected to increase because of improvements in Iron Dome's software and radar, built by Israel Aerospace Industries, as well as modifications to the system's operational doctrine.

Much of the upgrade effort has been paid for by the United States.

In May, the U.S. Congress approved almost $1 billion for Israel's planned four-tier missile defense shield, on top of the annual $3.1 billion in military aid, for fiscal 2013.

Iron Dome gets the lion's share with $680 million, on top of a $205 million U.S. appropriation in fiscal 2012.

Four Iron Dome batteries have been deployed since the system was certified operational in 2011. But military planners say at least 20 are needed to provide effective protection for the country.

The air force, which has charge of air defenses, is to take delivery of another two batteries, armed with extended-range interceptor missiles by the start of 2013.

Meantime, the air force is expecting to be supplied with extended-range interceptors for the existing batteries in the next few weeks.

"The air force would not reveal the new range of the upgraded system but officers said it would lead to a reduction in the number of batteries Israel will ultimately require to protect against short-range rockets fired from Lebanon and the Gaza Strip," The Jerusalem Post reported.