The video was an apparent attempt by the Osama bin Laden successor to counter the ongoing presence of Islamic State as the premier Sunni terrorist group, as well praise the rise of the Nusra front, an al-Qaida affiliate, which has seen massive gains in Syria filling the void left by ISIS as it continues to lose territory.
"We have to want the unity of the Mujahideen in Sham (Syria) so it will be liberated from the Russians and Western crusaders," said al-Zawahiri in his video address. "My brothers ... the matter of unity is a matter of life or death for you."
Al-Zawahiri condemns ISIS as "extremists," reinforcing al-Qaida’s well-known disdain for the rival group. Though ISIS originated from al-Qaida in Iraq (AQI), the group splintered in 2013 to form its own independent terrorist organization. The two organizations share a similar radical Islamic ideology, however, they vehemently disagree on tactics and strategy.