Writing in the CTC Sentinel, Yemen specialist and AQAP expert Gregory Johnsen argues that Yemen's ongoing war is benefiting both AQAP and local Islamic State affiliates, though the two groups are often at odds with each other. According to Johnsen, AQAP is taking advantage of the power vacuum that prevails in most of the country, but they're also taking advantage of the conflict in other ways:
As Saudi air strikes target Houthi fighters and military units loyal to former President Salih, AQAP can move into the newly cleared territory. In December 2015, AQAP did just that, retaking two of the towns in Abyan that it had held in 2011 and 2012. In the town of Ja`ar, which had previously served as the group’s de facto capital, AQAP killed the deputy commander of the city’s Popular Committee and reestablished control over Ja`ar, which AQAP refers to as Waqar....
AQAP has also dispatched fighters to conflict zones such as Taiz, where they join the local resistance against the Houthis and make local allies. One of AQAP’s primary goals is to integrate itself into Yemeni society. By fighting the Houthis alongside Yemenis, AQAP is creating new alliances, which its leaders believe will serve them well in the future....Prior to the Saudi-led bombing campaign, AQAP appeared to be in trouble. This is no longer the case. The group is acquiring more territory and, once again, is growing.
Local Islamic State supporters are taking advantage of another resource created by the war: sectarianism.
Just like in Iraq, where Abu Musab al-Zarqawi, the group’s spiritual founder, sparked a sectarian civil war by bombing Shi`a mosques, the goal in Yemen seems to be a radicalization of the religious landscape and the grafting of a sectarian war on to the country. The initial attack in March 2015 targeted what the Islamic State later claimed were “Shi`a mosques” in Sana`a....
The Islamic State’s primary goal throughout 2016 will be to further divide the country through sectarian attacks, recreating an Iraqi-style Sunni–Shi`a civil war in Yemen. The more sectarian the war becomes, the stronger the Islamic State will grow as it seeks to portray itself as the true defender of Sunni Islam.
Johnsen predicts that, in addition to fighting the Houthis and the Saudi-led coalition, AQAP and IS will likely go to war against each other in the coming months. He also warns that both organizations might increase their efforts to strike targets outside of Yemen, in order to boost their reputation and gain recruits.