Us and Them: Foreign Threat and Domestic Polarization

Can foreign threats reduce domestic polarization and, if so, under what conditions? This is an important question for the United States given the severity of internal division and the emergence of China as a potentially unifying external peril. We offer a novel theoretical argument about when external danger will rally Americans based on the nexus between the vividness of foreign danger and bipartisan elite agreement about the threat. We test our theory through a series of pre-registered survey experiments. We find that vivid foreign threats do not reduce domestic polarization and therefore the danger from China alone may not be sufficient to spur domestic unity. However, vivid foreign threats in combination with policymaker agreement about the threat does significantly reduce domestic polarization. This reduction in polarization does come at a cost: increased public willingness to violate use of force norms against China. Overall, our study establishes that foreign peril can reduce domestic polarization under certain circumstances, and demonstrates that elite reactions to foreign threats are highly important in shaping wider domestic effects.