Leading from behind (following) or the notion the US can sit it out has its limits. The bottom line from ISW.
Furthermore, the fact that the regime cannot conduct simultaneous operations on multiple fronts suggests that a military stalemate will persist, as the regime and rebel forces trade victories depending on resource allocation and reinforcements. This means that fighting will continue for a prolonged time, exacerbating sectarian tensions and displacing greater portions of the population with skyrocketing refugee numbers. These trends are causing significant problems for countries in the region that simply lack the economic and political capacity to deal with such spillover, and already violence has spread to Lebanon and Jordan.
Those arguing for a “let them fight it out” approach compartmentalize the Syrian conflict in ways that ignore these dynamics, which could quickly spark a regional conflagration that puts U.S. allies at risk and threatens U.S. strategic interests abroad. As Ambassador Fred Hof points out in a recent article, Assad’s victory in the war of narratives over the struggle for Syria has led to a belief in regime propaganda about the nature of this struggle. Yet, events in Damascus tell otherwise, and it would be wise to heed observe these lessons in order for the international community to take steps consistent with actual facts on the ground.