BEIRUT — A Syrian rebel group that the United States has labeled an affiliate of al Qaida in Iraq appeared Thursday to be on the verge of overrunning a government air base that’s used to launch helicopter strikes against rebel-held areas in Syria’s north.
According to the London-based Syrian Observatory for Human Rights and video of the fighting posted on the Internet, the offensive at Taftanaz, an air base near the road that links the Syrian cities of Idlib and Aleppo, was being led by the Nusra Front, which the State Department designated a terrorist organization last month.
Ahrar al Sham, another rebel group that, like Nusra, has called for establishing an Islamic state in Syria, is participating in the offensive, according to its Internet postings.
State Department spokeswoman Victoria Nuland offered an upbeat assessment of the rebel advance Thursday, saying that the likely takeover of the base was a sign that the abilities of the "armed opposition" were growing. She added that the capture of the base would help the rebel side by cutting off the Assad regime’s ability to resupply its troops in the north.
She didn’t acknowledge in her remarks that the assault on the base was spearheaded by Nusra, whose Arabic name is Jabhat al Nusra, and it was unclear whether she knew of the group’s role. State Department spokesmen didn’t respond to later requests for comment.
Nusra and Ahrar al Sham have proliferated across Syria in recent months, leading rebel advances and eclipsing the role of more moderate rebel groups. In its designation of Nusra as a terrorist organization, the State Department said that the group, which announced its presence a year ago with massive bombings in Damascus, was just another name for al Qaida in Iraq, a radical Sunni Muslim group responsible for the deaths of hundreds of U.S. troops and thousands of Iraqi civilians.
The declaration complicated U.S. support for the rebels, who are organized in a variety of fighting groups, each of which reports to its own commanders with its own political and religious beliefs. Obama administration officials had hoped that the designation would help channel aid to the rebels away from Nusra to more moderate factions. The designation, however, was immediately denounced by Sheikh Mouaz al Khatib, the head of the newly founded Syrian National Coalition for Opposition and Revolutionary Forces, which the United States has said should lead any post-Assad government.
Since then, Nusra influence appears only to have grown, with the group assuming a crucial role in rebel offensives across the country, including the current campaign to erode the government’s air power by seizing air bases.
In addition to Taftanaz, Nusra is leading the fighting at al Nayrab military airport in Aleppo, the country’s largest city. Islamist fighters also are likely to be playing a key role in the siege of a military airfield in the eastern province of Deir el Zour, where Nusra fighters led assaults that a McClatchy reporter witnessed in November.
Jeff White, a military analyst who studies Syria for the Washington Institute for Near East Policy, said rebels had hit at least one aircraft that was attempting to land at the Deir el Zour military airport in recent days and that they were closing on Mengh air base, another of the government’s northern bases. Earlier this year, Ahrar al Sham led fighting that partially shut Abu Duhor, another air base in the northern part of the country.
The fighting at Taftanaz underscores the growing influence in the rebel movement of conservative Islamic groups such as Nusra, which has grown in the space of little more than a year from a small clandestine organization that largely carried out bombings into a group that fields battalions of fighters across the country.
A recent report by the Quilliam Foundation in the United Kingdom estimated that Nusra now has about 5,000 fighters. Rebel supporters point out that that’s only about 10 percent of the anti-Assad forces, but given the fractured nature of the movement, that number of fighters probably means that Nusra is among its largest fighting organizations.
Rami Abdurrahman, the director of the Syrian Observatory for Human Rights, which tracks the violence in Syria, said he thought Nusra made up “30 to 40 percent” of the rebels’ effective fighting force. “Some groups work in some areas, and you think they are different groups, and they are actually part of Jabhat al Nusra,” said Abdurrahman, whose organization is considered the primary authority on the daily violence in Syria.
“They are getting bigger every day,” he added.
Analysts said the fighting prowess of Nusra and Ahrar al Sham was owed in part to the presence in their ranks of Syrians and Iraqis who fought the U.S. military and the Iraqi government during the U.S. occupation of Iraq, which ended in December 2011. In addition to their attacks on air bases, Nusra and Ahrar al Sham are leading the fighting in cities along Syria’s main north-south highway. Refugees fleeing violence in Damascus also said Nusra was at the forefront of fighting in that city’s Yarmouk district.
The highly visible successes of groups such as Nusra, which say they’re funded by individual donors from Syria and Persian Gulf countries such as Qatar and Saudi Arabia, have allowed them to add to their ranks. The fact that they’re often at the forefront of the fighting also has allowed them to capture weapons when they overrun military positions. Recent videos have shown the groups effectively using tanks and armored personnel carriers captured from government troops.
The rebels were likely also to have benefited in recent days from a fierce snow and rain storm in the region that’s prevented the Syrian government from using aircraft for much of the last four days. Rebels said the government instead had attempted to use surface-to-surface missiles to attack them at the base and to destroy equipment that they might capture.
Hannah Allam contributed to this article from Washington.
Enders is a McClatchy special correspondent. Email: email@example.com; Twitter @davidjenders