By MICHAEL R. GORDON
WASHINGTON — American intelligence analysts have concluded that a recent Israeli airstrike on a warehouse in Syria did not succeed in destroying all of the Russian-made antiship cruise missiles that were its target, American officials said on Wednesday, and that further Israeli strikes are likely.
Israel carried out an attack on July 5 near Latakia to destroy the missiles, which Russia had sold to Syria. While the warehouse was destroyed, American intelligence analysts have now concluded that at least some of the Yakhont missiles had been removed from their launchers and moved from the warehouse before the attack.
The officials who described the new assessment declined to be identified because they were discussing classified information.
Israeli officials have said that they do not intend to enter the civil war in Syria, but that they are prepared to prevent sophisticated weapons from falling into the hands of Hezbollah, the Lebanese militia, which has joined the war to support President Bashar al-Assad of Syria and which controlled the warehouse where the missiles were stored.
American and Israeli naval officials consider the missiles to be a serious threat to their ships.
After the Israeli attack, the Assad government sought to hide the fact that the missiles had been missed by setting fire to launchers and vehicles at the site to create the impression of a devastating blow, according to American intelligence reports.
The Pentagon did not respond to a request for comment. Israel has a longstanding policy of silence on pre-emptive military strikes.
Another factor that could lead to a military response by Israel is the continuing flow of weapons to the Assad government, some of which Israel fears may make its way to Hezbollah in neighboring Lebanon.
Russia, American officials say, recently sent SA-26 antiaircraft missiles to Syria, and it is also believed to be sending technical experts to help set up the system.
The Russians have also recently delivered two refurbished Mi-24 Hind helicopters to the Russian naval base at Tartus, Syria, for use by the Syrian military.
Russian officials have insisted that they are merely fulfilling old weapons contracts. But even the old contracts have involved the transfer of sophisticated arms.
In addition, American officials say that the transfer of Yakhont missiles to Hezbollah by Syria would violate an “end user agreement” that the Russian missiles would not be provided to third parties.
The July 5 attack near Latakia was the fourth known Israeli airstrike in Syria this year.
Providing new details, American officials said that it had been carried out by Israeli aircraft that flew over the eastern Mediterranean, fired air-to-ground missiles and never entered Syrian airspace. The route of the Israeli aircraft led to some erroneous reports that the attack had been carried out by an Israeli submarine.
In addition to targeting the Yakhont missiles, Israel carried out an airstrike in late January aimed at another system provided by Russia: a convoy of SA-17 surface-to-air missiles that Israeli officials believed were destined for Hezbollah.
Iran’s arms shipments are also a concern for the Israelis.
In May, Israeli warplanes conducted two days of airstrikes that targeted, among other things, a shipment of Fateh-110 missiles — mobile surface-to-surface missiles that had been provided by Iran and flown to Damascus, Syria, on transport planes that passed through Iraqi airspace.
The Fateh-110 missiles, which the Israelis feared were also intended for Hezbollah, have the range to strike Tel Aviv and much of Israel from southern Lebanon.
Iran has sent members of its paramilitary Quds force into Syria, under the supervision of Maj. Gen. Hossein Hamdani, a senior officer of the force who is in charge of operations in Syria and oversees Iran’s arms shipments to Hezbollah, according to American intelligence officials. Hezbollah’s attempt to acquire weapons is supervised by Shaykh Salah, a senior official in charge of the militia’s operations in Lebanon, according to American officials.
Iran has also pressed Iraqi Shiites to join the fight in Syria in support of the Assad government. That includes about 200 members of the Badr Corps, Iraqis who were supported by Iran during Tehran’s long war against Saddam Hussein, and who later returned to Iraq after he was ousted from power, American officials say.
The support of Iran and Hezbollah for the Assad government, and Israel’s military interventions, reflects how the conflict has drawn in outside powers.
Both Saudi Arabia and Qatar have been arming the Syrian rebels, and Congress recently dropped objections to a proposal by President Obama to provide training and light arms to them.