Rules and Allies: Foreign Election Interventions could not be timelier. Policy debates on foreign actions in national elections continue, from current congressional investigations about the US president’s request for foreign interference in the 2020 election to Russian meddling in elections in the United States in 2016 and in Madagascar in 2019. Such examples raise pertinent questions about how, when, and which governments choose to influence other countries’ elections and what effects that interference has. In their new book, Johannes Bubeck and Nikolay Marinov shed light on these important questions. Using formal models, case studies, and quantitative analyses of an impressive new dataset, they provide valuable insights for scholars and practitioners alike. The book is organized into seven chapters—literature review and theory (chaps. 2–3), data coding and patterns (chaps. 4–5), interventions by the United States (chap. 6), and extensions of the formal model to consider budgets, coups, and buying allies (chaps. 7–8)— plus an introduction and conclusion.

Bubeck and Marinov define foreign election interventions as preelection “deliberate attempt[s] by a foreign government to change the electoral rules or the election outcome” (p. 45). Conceptually, they distinguish between two types of election interventions: process and candidate. Process interventions are intended to influence how the election is run. Such international election support includes election observation (Susan Hyde, The Pseudo-Democrat’s Dilemma: Why Election Observation Became an International Norm, 2011), technical capacity assistance (Inken von Borzyskowski, “Resisting Democracy Assistance: Who Seeks and Receives Technical Election Assistance?” Review of International Organizations 11 [2], 2016), and other efforts to level the playing field and support a fair vote—or anti-process actions such as international support for gerrymandering, election violence, and (post-vote) international endorsements of clearly fraudulent processes (p. 80). In contrast to process interventions, candidate interventions are intended to influence who runs or is supported. Such partisan interventions are in favor of a particular candidate/party and can take the form of mobilization (support for a campaign or aid promises conditional on a certain candidate’s victory) or intimidation (threats of sanction or military invasion; pp. 89–90).

Partisan interventions have been documented for great powers (Dov Levin, “When the Great Power Gets a Vote: The Effects of Great Power Electoral Interventions on Election Results,” International Studies Quarterly 60 [2], 2016). Rules and Allies broadens the range of potential interveners and provides explanations for when one type of intervention is used over the other, when they are used in combination, and what effects we should expect them to have. In doing so, the book connects to a wealth of research on democracy assistance (Jon Pevehouse, Democracy from Above: Regional Organizations and Democratization, 2005; Daniela Donno, Defending Democratic Norms: International Actors and the Politics of Electoral Misconduct, 2013), buying allies (James Vreeland and Axel Dreher, The Political Economy of the United Nations Security Council: Money and Influence, 2014), and foreign-imposed regime change (Alexander Downes and Jonathan Monten, “Forced to Be Free? Why Foreign-Imposed Regime Change Rarely Leads to Democratization,” International Security 37 [4], 2013).

Bubeck and Marinov argue—and show empirically—that foreign powers are more likely to pick sides in an election as the policy positions of competing parties in the target country diverge (“polarization”) on a dimension of interest to the foreign power. Given divergence, a foreign power has incentives to support the candidate/party more aligned with it. For example, an outside power favoring the government candidate has incentives for partisan intervention on behalf of the government candidate. An outside power favoring the opposition has incentives to support the opposition candidate (allies) or the election process (rules), because improved election quality means less bias (incumbency advantage) and a more level playing field, which also help the opposition’s chances of winning. Outside powers often combine candidate and process interventions for higher impact. In addition to party polarization, other factors driving a potential intervener’s decision to meddle in foreign elections include the outsider’s preference for liberalism/democracy promotion, the target country’s geopolitical importance, historical ties between target and sender, and whether other interveners are likely to act (hegemony or war context). Finally, the authors argue that election interventions are consequential: they can change both election outcomes (who wins) and processes (election quality).

The empirical tests of these predictions are powered by a rich new dataset that provides information on potential interveners, the type and nature of election interference (pro/anti-process, pro/anti-candidate), and a measure of party polarization in the target country. Bubeck and Marinov manage the data-gathering effort with a clever research strategy: from all elections worldwide from 1945 to 2012 that were minimally competitive (based on Nelda data), they take a stratified random sample so that each country can be included once during and after the Cold War. This results in a sample of 262 national elections in 157 countries (about 10% of all elections). This strategy makes data collection feasible and the results generalizable. For each election, the authors identify potential interveners: global and regional powers, neighbors, former colonizers, those with oil interests, military bases, and ethnic diasporas, as well as international organizations. The coding decisions are meticulously documented in an expansive online appendix that links the relevant quotes from news sources to variable coding to maximize transparency and replicability. The authors set a new standard for documenting datasets of this kind.

Rules and Allies also provides many novel empirical insights. For example, foreign election intervention is widespread: of the 262 sampled elections, two-thirds had some form of election intervention: 52% had process interventions, 33% had candidate interventions, and 20% had both. Moreover, the United States is the most frequent intervener in both process and candidate interventions: “American presence is larger than the footprint of others by a large factor” (p. 119–20). Other common interveners regarding candidates are China, France, and the EU (p. 119); regarding process they are international organizations (the African Union and the EU), the United Kingdom, and France. Although the United States’ role in process interventions especially after 1990 may reflect increased commitment to liberalism and democracy promotion, its leading role in candidate interventions is noteworthy, because Western media usually note meddling by Russia.

The book makes several groundbreaking contributions and provides promising avenues for future research. One aspect that is worth noting is the measurement of process intervention, which seems to include a judgment on its effectiveness (p. 79). This implies that the coding is (at least partially) focused on outcomes, rather than presence or intent. In contrast, candidate interventions are coded based on intent (p. 89), and they capture whether the intervention happened or was designed to influence the outcome, regardless of its ultimate effectiveness. However, the outcome-focused coding of process intervention could impair our ability to examine whether such interventions matter, because effectiveness appears on both sides of the equation. It could also mean that a coding of 0 conflates two situations: that no process intervention happened or that the process intervention had no effect. That said, most example cases of process intervention mentioned in the book seem to be coded based on intent, so perhaps this is simply a discrepancy in the coding description that the authors may wish to clarify for future users.

A promising avenue for future work is assessing the effectiveness of election interventions. The book’s empirical tests are focused on establishing bivariate correlations between the key variables of interest. This is a necessary and important first cut; perhaps it is all that can be achieved in an already very ambitious book that presents a formal model to generate new theory, introduces a new dataset, and conducts empirical tests on drivers, effects, and extensions. Future work should expand on these tests by adding control variables to account for context and alternative explanations to deepen our knowledge of the drivers and consequences of interventions. For example, whereas the argument that polarization drives intervention is intuitive and persuasive, candidate popularity probably also plays a role. Even if polarization is high, actual intervention likely also depends on whether that ally is likely to win anyway, faces a tight election, or is unlikely to emerge victorious regardless of foreign intervention. Outsiders may also support the winning horse to secure economic profits in the target country, regardless of polarization (Michael Schwirtz and Gaelle Borgia, “How Russia Meddles Abroad for Profit: Cash, Trolls and a Cult Leader,” New York Times, November 11, 2019). For intervention consequences, future research could further examine effectiveness. Accounting for context and selection, does intervention “work” in achieving its intended goals, and under which conditions is that more likely? Which types and subtypes of intervention are more effective? When do election wars lead to intra- or interstate violence?

By providing the necessary data and a theory of intervention, Bubeck and Marinov have put researchers in an excellent position to pursue these and many other interesting questions of great policy relevance. The central theoretical contributions of this impressive book—drawing attention to partisan meddling, the trade-offs between partisan and process interventions, and election wars—may well become more important in the years to come, with disinformation campaigns being waged by both existing and rising powers. Rules and Allies is thus also highly recommended for scholars and practitioners interested in foreign affairs, diplomacy, security studies, and political communication.