The Post reports on the creation of a new alliance of Syrian opposition groups under the name of the “Islamist Alliance” and led by Jabhat al-Nusra:

American hopes of winning more influence over Syria’s fractious rebel movement faded Wednesday after 11 of the biggest armed factions repudiated the Western-backed opposition coalition and announced the formation of a new alliance dedicated to creating an Islamic state.

The al-Qaeda-affiliated Jabhat al-Nusra, designated a terrorist organization by the United States, is the lead signatory of the new group, which will further complicate fledgling U.S. efforts to provide lethal aid to “moderate” rebels fighting to topple Syrian President Bashar al-Assad.

The article portrays this as a setback to U.S. influence with the opposition, but it is more accurate to see this as confirmation that American attempts to exercise significant influence among predominantly Islamist rebels were always bound to fail. This news should also remind us that administration officials were misleading the public and Congress about the composition of Syrian rebel forces, and they were deliberately minimizing the role of Islamist groups in the opposition as part of their clumsy push for military action. This latest development doesn’t “complicate” U.S. efforts to arm part of the Syrian opposition so much as it makes the exercise almost completely irrelevant. The article explains:

The creation of the bloc nonetheless leaves Idriss’s council directly responsible for just a handful of small units, calling into question the utility of extending aid to “moderate” rebels, according to Charles Lister of the London-based defense consultancy IHS Jane’s.

Because the U.S. won’t and indeed legally cannot arm members of this “Islamist Alliance” on account of the involvement of Jabhat al-Nusra, that leaves the administration with the option of arming the weakest part of the weaker side in a civil war. That would seem to serve no purpose except to add more weapons to the mix, and there is no guarantee that any U.S.-provided weapons would not be lost to other groups that the U.S. has no wish to arm. That has always been true, but now it is impossible for anyone to miss.