December 2, 2012 | Posted by admin

WASHINGTON — The American effort to stem the flow of Iranian arms to Syria has faltered because of Iraq’s reluctance to inspect aircraft carrying the weapons through its airspace, American officials say.

Iraqi Civil Aviation Authority, via Reuters

An Iranian cargo plane during an inspection at Baghdad’s airport in October. Iraq has been reluctant to do inspections.

The shipments have persisted at a critical time for President Bashar al-Assad of Syria, who has come under increasing military pressure from rebel fighters. The air corridor over Iraq has emerged as a main supply route for weapons, including rockets, antitank missiles, rocket-propelled grenade and mortars.

Iran has an enormous stake in Syria, which is its staunchest Arab ally and has also provided a channel for Iran’s support to the Lebanese Islamist movement Hezbollah.

To the disappointment of the Obama administration, American efforts to persuade the Iraqis to randomly inspect the flights have been largely unsuccessful.

Adding to American concerns, Western intelligence officials say they are picking up new signs of activity at sites in Syria that are used to store chemical weapons. The officials are uncertain whether Syrian forces might be preparing to use the weapons in a last-ditch effort to save the government, or simply sending a warning to the West about the implications of providing more help to the Syrian rebels.

“It’s in some ways similar to what they’ve done before,” a senior American official said, speaking on the condition of anonymity to discuss intelligence matters. “But they’re doing some things that suggest they intend to use the weapons. It’s not just moving stuff around. These are different kind of activities.”

The official said, however, that the Syrians had not carried out the most blatant steps toward using the chemical weapons, such as preparing them to be fired by artillery batteries or loaded in bombs to be dropped from warplanes.

Regarding the arms shipments, Secretary of State Hillary Rodham Clinton secured a commitment from Iraq’s foreign minister in September that Iraq would inspect flights from Iran to Syria. But the Iraqis have inspected only two, most recently on Oct. 27. No weapons were found, but one of the two planes that landed in Iraq for inspection was on its way back to Iran after delivering its cargo in Syria.

Adding to the United States’ frustrations, Iran appears to have been tipped off by Iraqi officials as to when inspections would be conducted, American officials say, citing classified reports by American intelligence analysts.

Iran’s continued efforts to aid the Syrian government were described in interviews with a dozen American administration, military and Congressional officials, most of whom requested anonymity to discuss intelligence matters.

“The abuse of Iraqi airspace by Iran continues to be a concern,” an American official said. “We urge Iraq to be diligent and consistent in fulfilling its international obligations and commitments, either by continuing to require flights over Iraqi territory en route to Syria from Iran to land for inspection or by denying overflight requests for Iranian aircraft going to Syria.”

Iraqi officials insist that they oppose the ferrying of arms through Iraq’s airspace. They also cite claims by Iran that it is merely delivering humanitarian aid, and they call the American charges unfounded.

“We wouldn’t be able to convince them, even if we searched all the airplanes, because they have prejudged the situation,” Ali al-Musawi, the spokesman for Prime Minister Nuri Kamal al-Maliki of Iraq, said of the American concerns. “Our policy is that we will not allow the transfer of arms to Syria.”

Mr. Musawi acknowledged that one of the planes was not inspected until it was returning from Damascus, but said it was a simple error, not a deliberate effort to help the Iranians. “Mistakes sometimes occur,” he said.

But one former Iraqi official, who asked not to be identified because he feared retaliation by the Iraqi government, said that some officials in Baghdad had been doing the bare minimum to placate the United States and were in fact sympathetic to the Iranian efforts in Syria.

Michael R. Gordon and Eric Schmitt reported from Washington, and Tim Arango from Baghdad. David E. Sanger contributed reporting from Washington.