WASHINGTON — The United States, increasingly concerned about the threat posed by al-Qaeda’s Syria affiliate Jabhat al-Nusra to US national interests and allies, has discussed with Russia a proposal to target Jabhat al-Nusra as well as the so-called Islamic State (IS), under very strict conditions that Russia should meaningfully restrain Bashar al-Assad's regime for it to observe a partial Syria truce and allow in unfettered humanitarian aid.

“In Syria, as [IS] is losing territory in the east, its terrorist rival — Jabhat al-Nusra — is gaining ground in the west, putting down roots in Idlib province along the Turkish border,” Brett McGurk, the US special presidential envoy for the Global Coalition to Counter IS, said June 28 in written testimony to the Senate Foreign Relations Committee.

“With direct ties to Ayman al-Zawhiri, Osama bin Laden’s successor, Nusra is now al-Qaeda's largest formal affiliate in history,” McGurk said. “This is a serious concern, and where we see Nusra planning external attacks, we will not hesitate to act.”

While largely motivated by counterterrorism concerns, the United States believes the proposed measures could help shore up the cease-fire, reduce violence against civilians and allow more aid in, thus improving the environment for resumed Syria political transition talks, while the Syrian opposition fears weakening Jabhat al-Nusra would enable the Assad regime to make rapid gains on the ground, particularly in the Aleppo area.