By: Jennifer Cafarella –(ISW) – Key Takeaway: Both the Islamic State of Iraq and al-Sham (ISIS) and the al-Qaeda affiliate Jabhat al-Nusra (JN) plan to conduct attacks in Lebanon in the near term. Widely presumed to be enemies, recent reports of an upcoming joint JN and ISIS offensive in Lebanon, when coupled with ongoing incidents of cooperation between these groups, indicate that the situation between these groups in Lebanon is as fluid and complicated as in Syria. Although they are direct competitors that have engaged in violent confrontation in other areas, JN and ISIS have co-existed in the Syrian-Lebanese border region since 2013, and their underground networks in southern and western Lebanon may overlap in ways that shape their local relationship.
JN and ISIS are each likely to pursue future military operations in Lebanon that serve separate but complementary objectives. Since 2013 both groups have occasionally shown a willingness to cooperate in a limited fashion in order to capitalize on their similar objectives in Lebanon. This unusual relationship appears to be unique to Lebanon and the border region, and does not extend to other battlefronts. Despite recent clashes that likely strained this relationship in February 2015, contention between the groups in this area has not escalated beyond localized skirmishes. This suggests that both parties have a mutual interest in preserving their coexistence in this strategically significant area. In January 2015, JN initiated a new campaign of spectacular attacks against Lebanese supporters of the Syrian regime, while ISIS has increased its mobilization in the border region since airstrikes against ISIS in Syria began in September 2014. Conditions favor a continued limited détente between JN and ISIS past March 2015.