Part of a series of articles looking at the regional interests at stake in Syria's civil war. The full list is on the left of your screen.
Of Syria's five immediate neighbors, Lebanon is probably the most vulnerable to the repercussions of the two-year uprising that has morphed into a bitter sectarian civil war.
The Lebanese government – currently in a caretaker capacity since its resignation in March and pending the formation of a new cabinet – has adopted a policy of neutrality toward the Syria war. But the Lebanese are evenly and deeply divided between those that support and oppose the regime of Syrian President Bashar al-Assad.
That divide falls along sharp sectarian lines – mirroring the Syrian struggle – with Shiites led by the militant Iran-backed Hezbollah supporting the Assad regime, with the overwhelming majority of Sunnis siding with their co-religionists in Syri,a who comprise the bulk of the opposition.
Lebanon has always been the weaker vassal to its powerful Syrian neighbor and the Lebanese state exerts no direct influence over developments next door. However, substate actors in Lebanon are playing roles in Syria, chiefly Hezbollah, which has dispatched several thousand fighters to help assist the Assad regime defeat the rebels. Lebanese Sunnis have volunteered to fight with rebel groups or support them on a logistical basis from inside Lebanon.
It is difficult to envisage an ideal outcome for Lebanon if one side or the other triumphs in Syria. If the Assad regime manages to cling to power and reduce the threat posed by the rebels, Hezbollah will remain strong in Lebanon and the cross-regional alliance between the Shiite group and its backers in Damascus and Tehran will endure.
Such a scenario will deepen Sunni grievances in Lebanon and leave unresolved the continuing domestic debate over Hezbollah's status.
If the Assad regime falls and is replaced by a Sunni regime that moves closer to Saudi Arabia and the Sunni Gulf, Hezbollah will be isolated from Iran and will feel dangerously vulnerable. Any move by a newly emboldened Sunni community in Lebanon against a Hezbollah that still would be determined to retain its arms could exacerbate an already precarious security climate.
Perhaps the best scenario for Lebanon is a negotiated solution in Syria which compels rival actors to make compromises.
“This would spare Lebanon the likely knock-on effects of a decisive swing in either direction in Lebanon,” says Yezid Sayegh, a senior associate at the Carnegie Middle East Center in Beirut. “All parties, both in Syria and Lebanon, would have to accept the limits imposed by mutual compromise.”
The worst case scenario is that the Syria war continues for a prolonged period of time, accompanied by more spillover into Lebanon. In the past few months alone, Lebanon has witnessed cross-border rocket attacks by Syrian rebels into Shiite areas, deadly car bomb attacks against Sunni and Shiite targets, sectarian clashes and several roadside bomb attacks against suspected Hezbollah vehicles.
A continuation of the war in Syria would likely increase instability accompanied by further political paralysis and economic stagnation.