When new leaders come to office, there is often speculation about whether they will take their countries' foreign policies in different directions or stick to their predecessors' policies. We argue that when new leaders come to power who represent different societal interests and preferences than their predecessors, leaders may pursue new foreign policies. At the same time, in democracies, leadership selection processes and policymaking rules blunt leaders' incentives and opportunities for change. Democracies thus tend to pursue more consistent foreign policies than nondemocracies even when new leaders with different supporting coalitions assume office. Statistical analyses of three distinct foreign policy areas – military alliances, UNGA voting, and economic sanctions – provide support for our argument. In a fourth area – trade – we find that both democracies and nondemocracies are more likely to experience foreign policy change when a new leader with a different supporting coalition comes to power. We thus conclude that foreign policy responds to domestic political interests, and that, even as the interests supporting leaders change, democracies' foreign policies are no less stable than those of nondemocracies and often exhibit greater consistency.

A seemingly never-ending stream of observers claims that the populist emphasis on nationalism, identity, and popular sovereignty undermines international collaboration and contributes to the crisis of the Liberal International Order (LIO). Why, then, do populist governments continue to engage in regional and international institutions? This Element unpacks the counter-intuitive inclination towards institutional cooperation in populist foreign policy and discusses its implications for the LIO. Straddling Western and non-Western contexts, it compares the regional cooperation strategies of populist leaders from three continents: Hungarian Prime Minister Viktor Orbán, former Venezuelan President Hugo Chávez, and Philippine President Rodrigo Duterte. The study identifies an emerging populist 'script' of regional cooperation based on notions of popular sovereignty. By embedding regional cooperation in their political strategies, populist leaders are able to contest the LIO and established international organisations without having to revert to unilateral nationalism.

The field of grand strategy is exceptionally American-centric theoretically, methodologically and empirically. Indeed, many scholars treat the United States as a unique case, and thus incomparable. This Element addresses the shortcomings of this approach by developing a novel framework for the purpose of systematic comparison, both within and among different countries. Using the United States as a benchmark, three dimensions are considered in which grand strategy can be compared: first, attributes of the major types commonly discussed in the literature; second, similarities and differences in the implementation of grand strategies over time, using US strategic relations with contemporary Russia as an example; and finally, across space, properties of the grand strategies that are interactively employed by other major powers in relation to the United States in the Indo-Pacific. The Element can be used by scholars and students alike to expand analysis beyond the confines that currently dominate the field.

Research on international norms has yet to answer satisfactorily some of our own most important questions about the origins of norms and the conditions under which some norms win out over others. The authors argue that international relations (IR) theorists should engage more with research in moral psychology and neuroscience to advance theories of norm emergence and resonance. This Element first provides an overview of six areas of research in neuroscience and moral psychology that hold particular promise for norms theorists and international relations theory more generally. It next surveys existing literature in IR to see how literature from moral psychology is already being put to use, and then recommends a research agenda for norms researchers engaging with this literature. The authors do not believe that this exchange should be a one-way street, however, and they discuss various ways in which the IR literature on norms may be of interest and of use to moral psychologists, and of use to advocacy communities.

The 2016 US election highlighted the potential for foreign governments to employ social media for strategic advantages, but the particular mechanisms through which social media affect international politics are underdeveloped. This Element shows that the populace often seeks to navigate complex issues of foreign policy through social media, which can amplify information and tilt the balance of support on these issues. In this context, the open media environment of a democracy is particularly susceptible to foreign influence whereas the comparatively closed media environment of a non-democracy provides efficient ways for these governments to promote regime survival.

This Element provides an explanation for the power of weak states in international politics, focusing on the case of international climate negotiations at the United Nations. The author points to the pitfalls of assuming that weak countries elicit power from their coordinated salience for climate issues. Contrastingly, it is argued that weak states' influence at global climate negotiations depends on the moral authority provided by strong states. The author maintains that weak states' authority is contingent on international vulnerability, which intersects broader domestic discussions of global justice, and pushes the leaders of strong countries to concede power to weak countries. New empirical evidence is shown in support of the theory.