Annual Review of Political Science - Volume 23, 2020

We live in a digital world. This fact has significant consequences for warfare. Two technologies in particular, cyber and drones, feature in military and intelligence operations and in scholarship. In addition, a new vein of scholarship is examining how advances in artificial intelligence have the potential to shape the future of warfare. While scholars disagree about the consequences of these technologies for international politics, they tend to agree that their consequences are mediated by the ability of military organizations, whether state or nonstate actors, to use them effectively in relevant military scenarios and in the pursuit of political ends. Studying newer military technologies, with less empirical evidence than is available for technologies that have been around for decades, also generates methodological challenges for research.

To what extent are Internet users resilient to online censorship? When does censorship influence consumption of information and when does it create backlash? Drawing on a growing literature on Internet users’ reactions to censorship, I posit that awareness of censorship, incentives to seek out information, and resources to circumvent censorship are essential to resilience to censorship. I describe how authoritarian regimes have adapted their strategies of censorship to reduce both awareness of censorship and demand for uncensored information.

We review the literature on the rise of identity politics and populism in Europe. Populist parties have gained large vote shares since the Great Recession of 2008. We observe in many countries, and even in the European Parliament, a transformation of the main dimension of politics from the left–right cleavage to a new cleavage opposing the mainstream parties to populist parties. We examine how this transformation relates to changes in voter attitudes and the adjustment of political parties to these changes. Two main types of causes for the rise of populism have emerged: economic and cultural. In reviewing the evidence, we find a complex interaction between economic and cultural factors. Economic anxiety among large groups of voters related to the Great Recession and austerity policies triggers a heightened receptivity to the messages of cultural backlash from populist parties.

Does ethnic diversity erode social trust? Continued immigration and corresponding growing ethnic diversity have prompted this essential question for modern societies, but few clear answers have been reached in the sprawling literature. This article reviews the literature on the relationship between ethnic diversity and social trust through a narrative review and a meta-analysis of 1,001 estimates from 87 studies. The review clarifies the core concepts, highlights pertinent debates, and tests core claims from the literature on the relationship between ethnic diversity and social trust. Several results stand out from the meta-analysis. We find a statistically significant negative relationship between ethnic diversity and social trust across all studies. The relationship is stronger for trust in neighbors and when ethnic diversity is measured more locally. Covariate conditioning generally changes the relationship only slightly. The review concludes by discussing avenues for future research.