Al Qaeda in Yemen rebukes ISIS

(CNN) -- Al Qaeda's affiliate in Yemen -- al Qaeda in the Arabian Peninsula -- strongly rebuked ISIS in a video released Friday, declaring ISIS leader Abu Bakr al-Baghdadi's declaration of an Islamic caliphate to be illegitimate.

The statement, delivered by one of AQAP's top clerics -- Harith bin Ghazi al-Nadhari -- is a significant setback to ISIS efforts to assume leadership of the global jihadist movement a week after groups in Egypt and Libya joined the ISIS fold.

ISIS and al Qaeda's top leadership in Pakistan had a bitter falling out earlier this year, and al Qaeda and ISIS fighters have been fighting each other in Syria, but AQAP had until now stayed above the fray, calling for both sides to reconcile and pool resources to strike the United States.

But when al-Baghdadi declared in an audiotape released last week his Islamic State had expanded to Yemen, as well as other Middle Eastern countries, it was too much for the AQAP leadership to stomach.

By claiming Yemen for his caliphate, al-Baghdadi had called into question the very right of AQAP to exist as a separate and autonomous jihadi group, leaving its leadership no choice but to push back.

"We did not want to talk about the current dispute and the sedition in Syria... however, our brothers in the Islamic State ... surprised us with several steps, including their announcement of the caliphate [and] they announced the expansion of the caliphate in a number of countries which they have have no governance, and considered them to be provinces that belonged to them," al-Nadhari stated, according to a translation by the SITE intelligence group.

"The announcement of the caliphate for all Muslims by our brothers in the Islamic State did not meet the required conditions," al-Nashari argued, because other jihadi groups were not consulted.

The cleric also criticized ISIS for "going too far in interpretations in terms of spilling inviolable blood under the excuse of expanding and spreading the power of the Islamic State."

And in a repudiation of al-Baghdadi's claim to supremacy among jihadis, he reaffirmed the group's pledge of allegiance to al Qaeda leader Ayman al-Zawahiri and Taliban leader Mullah Omar.

In forcing AQAP to publicly choose sides, al-Baghdadi appears to have badly miscalculated. AQAP leader Nasir al Wuhayshi, despite being named the number two of al Qaeda globally by al-Zawahiri last year, had been careful not to weigh in publicly on the dispute between al Qaeda and ISIS, restricting himself only to a poem he released in July praising his Egyptian boss.

In February, the general command of al Qaeda declared it had severed ties with ISIS because of its insubordination and its brutal tactics against fellow Muslims.

By then, Jabhat al Nusra, al Qaeda's affiliate in Syria, and ISIS were already fighting each other in parts of northern Syria. Although U.S airstrikes against both groups in recent weeks have led to ceasefires and some cooperation at the local level against moderate rebel groups, relations have remained tense.

AQAP divisions over ISIS

The AQAP leadership's rebuke of ISIS is not likely to go down well with all its members. Wuhayshi had avoided previously criticizing al-Baghdadi because he feared it might exacerbate divisions inside his own group. ISIS's rapid territorial expansion in Iraq and Syria electrified many jihadis in Yemen, and led to disagreements within the group.

"We have discussed that which resulted from the dispute and the infighting in Sham (Syria) with debate and argument ... however, we pardoned those who raised such issues," al-Nadhari acknowledged in the video released Friday.

Everything to know about the rise of ISIS

In January, one mid-level AQAP figure -- Mamoun Hatem

-- tweeted his support for ISIS as its feud with al Qaeda heated up, prompting speculation of discord within its ranks.

This past summer, Abdul Majid al Raymi, a leading Yemeni Salafi-jihadi preacher long admired by AQAP, also came out in support for ISIS, asking his large number of followers in Yemen to do the same.

The U.S. air campaign against ISIS further boosted the popularity of ISIS in Yemeni jihadi circles, prompting AQAP to release a message of solidarity.

"Their blood is our blood, and their wounds are in our hearts, and supporting them is a duty upon us. Once we find a way to afflict America, we will follow it, Allah permitting," the group stated in a statement posted on Twitter on August 14, and translated by SITE.

Even in disagreement, respect

All this has made AQAP leaders tread carefully. Even in rebuking ISIS, AQAP's al-Nadhari was careful to refer to al-Baghdadi respectfully as "sheikh."

The cleric expressed hope that divisions between ISIS and Nusra could be healed and left the door open for fences to be mended between AQAP and ISIS if al-Baghdadi withdrew his fatwa claiming Yemen for his caliphate.

"We express our utmost joy to having received good news about what we heard of signs of stopping the infighting among the mujahideen in the Sham front [Syria]," al-Nadhari stated.

Despite the possibility of growing discord within AQAP, there are no signs of any immediate threat to Wuhayshi's leadership.

To date, no senior leader within AQAP has broken ranks and come out in favor of ISIS. Wuhayshi, by all accounts, remains exceptionally popular with the group's rank-and file-fighters, who have been energized by a call to arms to fight Shia Houthi fighters who recently took control of Sana'a.

But AQAP's rebuke of ISIS increases the chances of a splinter group emerging. Last week, a group calling itself Mujahideen in Yemen recorded a tape pledging loyalty to Baghdadi.

Egyptian terror group pledges alliance to ISIS

For ISIS, the rebuke by AQAP is a significant setback after recent wins elsewhere in the region in its jockeying with al Qaeda for pre-eminence in the global jihadi movement.

Last week, Ansar Beit al Maqdis, an increasingly powerful Egyptian group based in the Sinai, declared allegiance to al-Baghdadi, as did veteran Libyan ISIS fighters who have taken control of Derna, a major town in eastern Libya. Small splinter factions of the Pakistani Taliban and al Qaeda in North Africa, as well as a group of fighters in Saudi Arabia, also declared their support.

The AQAP move may see the Yemeni group step up cooperation with Jabhat al Nusra in Syria. U.S. officials believe AQAP has shared sophisticated bomb-making technology with the Khorasan Group, a Nusra-linked outfit of veteran al Qaeda operatives plotting terrorist attacks against Western aviation.

The prospects of ISIS also receiving such bomb-making know-how from the Yemeni group appear to have dimmed.