The bombing of Syria’s national security headquarters, which killed key figures in the government, is evidence of expanding instability, but not of a regime on the verge of collapse. The attack and others like it have not significantly altered the Syrian uprising’s most enduring challenge: the inability of its fragmented opposition to congeal. This challenge, coupled with the rebellion’s lack of an inclusive vision for Syria’s minorities, and the troubling developments today, should give proponents of intervention pause.

America, Russia, Turkey, and the Gulf Arab states have all called on Syria’s fractured opposition to unify. A commitment to inclusion today could break down tomorrow, and such divisions could set the stage for an even bloodier ethno-sectarian civil war in a post-Assad Syria. Discord persists despite rebel attacks on regime officials and security forces. In fact, conflicting reports about the most recent bombing in Damascus—whether it was carried out by the Free Syrian Army, which claimed responsibility, or a cabinet member’s personal bodyguard—points to the difficulty of discerning the exact nature of the opposition.

Islamists, for instance, seem intent on hijacking the struggle for a democratic Syria. In May, the Washington Post’s Karen DeYoung and Liz Sly reported that despite U.S. hopes that minorities would unite under the Sunni-led Syrian National Congress, Syria’s Christians, Kurds, Druze, and Alawite sect, “All have resisted what they say is the group’s domination by the Muslim Brotherhood.”

That same month, Pentagon spokesperson Navy Captain John Kirby told reporters that defense officials believe “al-Qaida has some presence inside Syria and interest in fomenting violence in Syria.” He added, “We do not believe they share the goals of the Syrian opposition or that they are even embraced by the opposition … The sense that we get is that it is primarily members of [al-Qaida in Iraq] that are migrating into Syria.”

Similarly, U.S. Director of National Intelligence James Clapper warned earlier this year that al Qaeda-aligned forces coming from neighboring Iraq—a country that the United States occupied for nearly a decade—had carried out explosions in Damascus:

The two bombings in Damascus in December … and then the two additional bombings in Aleppo, both of which were targeted against security and intelligence buildings … had all the earmarks of an al Qaeda-like attack.  So we believe that al Qaeda in Iraq is extending its reach into Syria.

Rather than exercise restraint, the rise of Syria’s Islamists has encouraged Washington to intervene. Last month, the New York Times reported that U.S. officials had ordered a small number of C.I.A. officers to help funnel “automatic rifles, rocket-propelled grenades, ammunition and some antitank weapons,” across the Turkish border through intermediaries in Syria who include the Muslim Brotherhood, all paid for by Turkey, Saudi Arabia and Qatar. The justification was to keep weapons out of the hands of al Qaeda-allied groups, which is not reassuring. The most infamous instance of planners in Washington assisting the arming of rebels was in the 1980s in Afghanistan—a country that years later turned into an al Qaeda sanctuary.

The Syrian opposition’s failure to unite, combined with the ascendance of Islamists and al Qaeda-linked jihadists, complicates, among other things, the Western response to the Assad regime’s continued massacre of its people. For now, these divisions will prove more damaging to the Syrian uprising than the uprising’s attacks on the regime’s iron-fist.