The backlash within Syria to the U.S. decision to designate the Syrian-based jihadist group Jabhat al-Nusra as a terrorist organization has been swift. Opposition to the designation, which was officially announced on Dec. 11, extends well beyond groups ideologically sympathetic to Jabhat al-Nusra's radical goals. After more than 40,000 deaths, the starvation and torture of many, and the sadistic tactics of the Assad regime, Syrians now want the fall of the regime more than ever -- even if that means temporarily embracing groups with suspect long-term goals.

The Barack Obama administration's designation of Jabhat al-Nusra asserts that the group is an extension of al Qaeda in Iraq (AQI) -- merely one of the terrorist organization's aliases. Whether this is the case or whether the administration is issuing the designation as part of a political effort to convince the opposition to shun Jabhat al-Nusra, the move will likely fail to marginalize the group at this juncture. Following the fall of the regime, however, it could help sideline the most destructive influences trying to gain a foothold in post-Assad Syria.

The reaction among anti-Assad Syrians was perhaps best captured by an image that appeared on Facebook shortly after news of the planned designation broke last week. In the picture, residents of the northwestern town of Kafr Anbel hold up a poster showing Obama pointing accusingly toward a flag associated with Jabhat al-Nusra, saying "Terrorism." Behind the U.S. president, however, is Syrian President Bashar al-Assad standing triumphant on a pile of murdered Syrian civilians.

The image reflects the reality that the Syrian opposition simply does not view Jabhat al-Nusra as the primary threat to the country -- that designation still belongs to Assad's murderous army. Nor is it lost on Syrians that the Obama administration has provided scant military assistance in their efforts to topple the regime -- but is now singling out a rebel group that has become perhaps their revolution's most effective fighting force. This is a view that seems to extend well beyond Jabhat al-Nusra's ideological milieu: None of the individuals in the Kafr Anbel picture, for example, look like Islamists or Salafis.

Islamists, of course, have also condemned the Obama administration's decision. The popular Islamist group Suqur al-Sham ("the Falcons of Greater Syria") -- a more mainstream faction -- released a statement from its leader Ahmad 'Issa al-Shaykh on Dec. 9 rejecting the designation. The Islamist group stressed the importance of unity and cohesion between the different rebel factions and emphasized that Jabhat al-Nusra is like any other brigade working to overthrow the Assad regime. Shaykh refers to Assad's army as the real terrorists in Syria, and concludes with a reminder of U.S. "crimes" in Afghanistan and Iraq.

Opposition to the designation is only gaining momentum within Syria's anti-Assad groups. The Syrian National Council (SNC), which was the face of the revolution until being superseded by a new coalition, released a statement rejecting the move. The SNC, which still maintains considerable influence in opposition politics, goes on to explain that the Assad regime's massacres are the true terrorism in Syria today. The Syrian Muslim Brotherhood also stated that the decision to designate Jabhat al-Nusra was "very wrong." The recently elected chief of staff of the Free Syrian Army, Brig. Gen. Salim Idriss, piled on, saying Jabhat al-Nusra was not a terrorist organization, and "depends on young, educated Syrians" for its efforts.

Syrians are also planning to take to the streets to express their solidarity with Jabhat al-Nusra this week. A coalition of coordinating committees and rebel battalions has called for demonstrations this Friday under the slogan "No to the Interference of America -- We Are All Jabhat al-Nusra." The statement originally had 29 signatories, but now contains more than 100.

Even more worrisome from the perspective of the United States, there are tentative signs that Jabhat al-Nusra has also been providing local services. While the designation signals that the U.S. government is committed to isolating the group, its heroics on the battlefield and its work to provide for the basic needs of the Syrian people could signal that it is becoming embedded within the social fabric of the population.

Jabhat al-Nusra's provision of social services was first highlighted in an Aug. 19 video released by the group, titled "Fulfillment of the Vow #2." The video shows the group's Lajna al-Ighatha ("Relief Committee") providing foodstuffs to individuals in rural areas surrounding the eastern city of Deir al-Zour. More recently, according to the Syrian news site al-Zaman al-Wasl, Jabhat al-Nusra provided more than 20,000 bundles of bread to individuals in Aleppo governorate after an acute crisis occurred. The Coordinating Council in Aleppo, a local civilian opposition body established in August 2011, also reported that Jabhat al-Nusra provided barrels of fuel for an Aleppo hospital to run generators after long power outages.

In a conference call today, a senior U.S. official explained the designation by saying that it was intended to "expose" Jabhat al-Nusra, and make it clear that the group's ideology "has no role in post-Assad Syria." If it succeeds in doing that, the decision will have been the correct one. But given the intense opposition to this move by many quarters of the opposition, the administration should rededicate itself to efforts that show it is on the side of the Syrian people -- not only by providing humanitarian aid to areas affected by Assad's scorched-earth policy, but also by recognizing the new Syrian opposition coalition and providing weapons to more moderate rebel groups.

The day after the Assad regime falls, all Syrian groups will struggle to implement their vision of their country's future -- and secular, liberal, or even "moderate" Islamist factions will be starkly at odds with radicals like Jabhat al-Nusra. Slapping a terrorist designation on Jabhat al-Nusra is only the first step in what must be a sustained effort to ensure that these extremists' support breaks down in the long term, and Syrians do not trade the Assad regime for a society run by jihadists.

Aaron Y. Zelin is the Richard Borow fellow at The Washington Institute.