Hezbollah's ability to use relatively advanced weapons in the last week of fighting against Israel, as well as the variety of its armaments, has surprised U.S. military experts, current and former officials involved in Middle East policy said.
Hezbollah has gained attributes more often associated with a national military -- fixed training bases, rocket-launching facilities, well-trained artillerymen -- than with a guerrilla or terrorist group, they said.
The officials, speaking on condition of anonymity because intelligence matters are involved, said Hezbollah fighters, once viewed as a ragtag group of guerrillas, appear to have received training by Iran in sophisticated missile technologies. Some of the training may have taken place in Iran, they said.
"The analysis around here is they have more expertise than the Lebanese military," a senior U.S. military official said.
U.S. defense and intelligence officials said that -- despite the speculation of some analysts, including Israeli officials, that Iran was directly involved in the combat -- there was little evidence that its special operations groups were fighting alongside the Shiite Muslim militants.
Former officials warned that Hezbollah's closed nature and the politics involved in such assessments made any determination of Iranian intent highly uncertain.
"This is an opaque universe that's very hard to penetrate, and there's a lot of extrapolation based on bits of information," said Jon B. Alterman, a senior fellow at the Center for Strategic and International Studies in Washington, who worked on Mideast issues in the State Department under President Bush.
Israeli intelligence officials said assistance, including basic weapons and supplies, continues to flow from Iran.
One Israeli intelligence official said there was new evidence that Iran had stepped up arms shipments through Camp Zabadani, a longtime base that the Iranian Revolutionary Guard maintains in Syria, near the Lebanese border.
"The order to increase assistance" to Hezbollah fighters came "directly from Tehran with the approval of the bureau of the leader Khamenei," the official said, referring to Ayatollah Ali Khamenei, Iran's supreme leader. He asked to remain anonymous for security reasons.
"The assistance mainly includes a large amount of weapons as well as ammunition, cash, field rations," he said.
Iranian assistance could extend Hezbollah's ability to sustain the current fighting. During the last three days, Israel has detected the movement of several shipments of weapons and supplies from Iran to the Revolutionary Guard base as well as to nearby warehouses, where arms have been stockpiled in recent years, Israeli officials said.
An Israeli air raid Tuesday destroyed an arms-laden convoy of trucks that had originated at Camp Zabadani, entered Lebanon and was bound for the militants, the Israeli intelligence official said. He cited a summary of intelligence gathered through surveillance technology and other means.
The shipments from Iran to Lebanon via Syria in the last few days included FL-10 naval missiles, which are based on Chinese technology and have a range of nine to 18 miles, as well as Katyusha short-range artillery rockets and Iranian-made Fajr 3 and Fajr 5 missiles, the Israelis allege.
The strongest evidence of Iranian involvement with Hezbollah involves the missile used to cripple an Israeli ship off the coast of Beirut on Friday. U.S. officials also point to Hezbollah rocket attacks deep inside Israeli territory.
If the missiles that struck the ship and landed in Israeli cities were "fired by Hezbollah themselves, they would have had to have training in these missile technologies," the senior U.S. military official said, noting that such training probably would have come from Iranian military schools.
"If not Iranians, surely they were people trained in Iran," said the Israeli intelligence official, speaking of the personnel who launched the anti-ship missile. That rocket was believed to be a C-802, Iranian-produced and based on Chinese technology.
"That missile had never been fired in Lebanon before, and it hit its target. In order to learn that system, you have to fire the missile. We would have learned of such tests if they had happened in Lebanon," he said.
U.S. officials were also surprised when Israel said that some of the longer-range artillery rockets that had hit northern Israel were made by Syria, said David Schenker, until recently the Pentagon official overseeing Lebanon policy.
"There was broad knowledge there was Iranian involvement; there was a broad-based thought Syria was too smart to do something like that," said Schenker, of the Washington Institute for Near East Policy.
Israeli military and intelligence officials have been warning for years about the increasing number of long-range, Iranian-supplied rockets flowing into the hands of Hezbollah.
U.S. and Israeli analysts and officials believe that Hezbollah's weaponry includes thousands of the relatively unsophisticated Katyushas, as well as about 100 longer-range Fajr 3 and Fajr 5 rockets, which can travel about 25 and 75 miles, respectively.
Of greater concern to Israel, and the subject of much more speculation, is whether Hezbollah possesses the Iranian-made Zelzal 2 missile.
The International Institute for Strategic Studies, a London-based information clearinghouse, estimates the range of that weapon at 60 to 240 miles, which would put virtually all Israeli cities within striking distance of southern Lebanon.
The Israeli government says Hezbollah has had at least four of the missiles, one of which it says it destroyed and another it says malfunctioned.
The U.S. military offers mixed assessments of Israel's success in destroying Hezbollah rockets. One Pentagon official said that because of the mobility of most of the estimated 10,000 to 12,000 rockets in Hezbollah's arsenal, Israel has been forced to focus on command and control sites and other fixed bases.
The Pentagon official said only about 1,000 of Hezbollah's rockets are believed to have been fired or destroyed.
"The Israelis believe they have had some effect, but Hezbollah remains in this fight," he said. "They can sustain this for quite some time."
Spiegel reported from Washington and Rotella from Paris. Times staff writer Greg Miller in Washington contributed to this report.