The war of words between al-Qaeda and the "Islamic State of Iraq and the Levant" (ISIL) provides mounting evidence of the rift between the two groups, which seek to undermine each other with increasing viciousness, experts said.
As each group struggles with external challenges, infighting and fighter recruitment and retention, their leaders are taking every opportunity to pounce on each other and tarnish the others' image, experts told Al-Mashareq.
Al-Qaeda leader Ayman al-Zawahiri's most recent audio message, directed at ISIL and its leader, is a continuation of this verbal jousting, they said.
In a message posted online on January 5th, al-Zawahiri attempts to take advantage of the difficult situation ISIL is going through to lure its fighters away from ISIL and into al-Qaeda's ranks.
This move comes amid numerous reports in the recent period of increasing ISIL defections and rifts among its elements, especially in Syria.
In his message, al-Zawahiri accuses ISIL leader Abu Bakr al-Baghdadi of "lying" and "slandering" al-Qaeda in an attempt to tarnish its image, and denounces ISIL elements who supported these actions.
He complains that al-Baghdadi had spread allegations that al-Qaeda opposes sectarian attacks on Shia and is willing to co-operate with Christian leaders.
"The liars insist upon their falsehood, to the extent that they claimed we do not denounce Shia as infidels," al-Zawahiri said.
"The new message by the leader of al-Qaeda, that he devoted to attacking ISIL and its leader, Abu-Bakr al-Baghdadi, confirms once again the depth of the chasm between the two groups and the ferocity of the ongoing battle between them," said terror group specialist Maj. Gen. Wael Abdul Muttalib, a retired Egyptian military officer.
Disagreements between the two groups have been in evidence since around the time ISIL emerged and broke away from al-Qaeda's control, he told Al-Mashareq.
"Al-Zawahiri is clearly taking advantage of the pressures ISIL is facing amid the international war waged against it in Iraq and Syria," Abdul Muttalib said.
The al-Qaeda leader is trying to "steal" ISIL elements and thereby lay claim to al-Baghdadi's "caliphate", he added, pointing to numerous recent reports of ISIL elements fleeing areas controlled by the group or defecting to other groups.
These include al-Qaeda splinter group al-Nusra Front (ANF), also known as Fatah al-Sham Front, he said.
Through his message, al-Zawahiri also sought to emphasise the "constants that al-Qaeda has adhered to from its inception to date, namely fighting Western countries and Arab regimes that reject extremist ideology", he said.
"It appears that his entire speech is directed at ISIL elements and other jihadist factions that broke away from al-Qaeda's control in the past period and are primarily present in Syria," Abdul Muttalib said.
Fueling sectarian conflict
"Al-Zawahiri's recent speech will bring sectarian tensions between Sunnis and Shias to the fore once again and on a large scale, especially in Syria and Iraq," said Al-Azhar University professor and political researcher Abdul Nabi Bakkar.
In the recent period, al-Qaeda has somewhat abstained from attacking civilians, he told Al-Mashareq, not because it no longer attacks civilians as it claims, but rather because stringent security measures in Iraq due to the fight against ISIL have made it difficult to carry out acts of terrorism.
Bakkar said it is possible to infer several things from al-Zawahiri's message, especially with regard to the relationship between al-Qaeda and ANF.
By saying that attacking members of the international coalition remains a priority, but adding that "the circumstances of every jihad arena must be taken into account in the interest of jihad", al-Zawahiri gave ANF a pretext to shift its policies, he said.
This gives ANF implicit justification, based on the prevailing circumstances, to protect its existence and the areas under its control, Bakkar said.
Military analyst Maj. Gen. Abdul Karim Ahmed, a retired Egyptian army officer, warned of the possible violence al-Zawahiri's message might trigger among the supporters of al-Qaeda, ISIL and others who espouse extremist ideology.
"This call could spur both groups and their supporters to carry out terrorist attacks around the world in an attempt to outdo each other in proving their existence and laying claim to the so-called caliphate," he told Al-Mashareq.
This could lead to a "bloodbath", he said.
The competition between al-Qaeda and ISIL would be over which group has the "the right to raise the banner of jihad", he said -- a determination based on which group has killed the most "infidels" in its quest to establish a caliphate.
"ISIL clearly snatched that banner away from al-Qaeda at its inception, and here is al-Qaeda trying once again to raise the banner, taking advantage of the circumstances ISIL is going through," he said.
The terror tactics employed by both groups are similar, he said, adding that "this requires that international counter-terrorism efforts, particularly intelligence work, be intensified to foil any attempt at carrying out a terrorist attack".