The Syrian refugee crisis may soon be the largest since the Second World War. This Article is the first to analyze the devastating fallout of this crisis, and to propose a novel approach to a perennial international law problem at its center. Nearly all of the more than 4 million refugees that have fled the conflict in Syria are concentrated in five countries in the region. These countries do not have the resources to sustain these refugees and there is no principled basis for the current distribution of the responsibility of protecting Syrian refugees. Instead, geo-graphic proximity to conflict and porousness of borders remain the primary determinants of which nations bear the heaviest cost. The resulting distribution of refugees threatens Syrian lives, regional stability and international security. Despite the gravity of the Syrian refugee crisis, however, states can mitigate it if they cooperate to share the cost of protecting these refugees. Regrettably international refugee law offers no basis for achieving this cooperation. This Article proposes a means of achieving international cooperation to share the cost of protecting refugees fleeing mass atrocities, such as those fleeing Syria. It uses an as yet unexplored avenue to do so: the international doctrine of the responsibility to protect (RtoP). International actors and scholars have typically focused on when and how RtoP facilitates state cooperation for coercive international action against human rights violators. This Article argues for a new, non-coercive use of the existing doctrine — facilitating international refugee cost-sharing. It proposes a mechanism for achieving this refugee cost-sharing to address rising international displacement from conflict, and applies it to the Syrian refugee crisis to illustrate how the mechanism would function. Some scholars will question the suitability of RtoP as a frame for pursuing international cooperation for refugee protection, in light of the concerns that commentators have generally raised regarding the doctrine in other contexts. To overcome these concerns, this Article proposes a new approach to how international actors develop and apply RtoP even beyond the context of refugee protection.