The 2016 US presidential election seared the problem of foreign electoral interference into the mind of the global public. But partisan talking points have often occluded a clear understanding of the vexing questions that surround this issue: How can we know what are the electoral effects of foreign interference? Should we consider electoral interference an act of war, a distasteful yet common tool of statecraft, or something in between? Two excellent recent books shed light on these questions: Dov Levin’s Meddling in the Ballot Box and Jens David Ohlin’s Election Interference. Reading these books in sequence (Levin’s first, followed by Ohlin’s), one is struck by how they complement each other.

Levin’s account provides a historical picture of electoral interference, as employed by both the United States and the USSR/Russia over a 50-year period (from 1946 to 2000), constructed using archives of US and Soviet/Russian covert actions. It should come as no surprise that the United States has been a frequent meddler in other countries’ elections—in fact, a far more active meddler than the USSR/Russia—at least during the Cold War. Moreover, although Russia’s efforts were mainly focused on Europe, US interference spanned global regions (pp. 152–56).

Levin’s operative definition of “partisan electoral intervention” is broad, encompassing both covert and overt tactics, ranging from overt threats or promises conditional on the election outcome, to providing campaign funds or training to the favored party, to covertly engaging in disinformation and other “dirty tricks” (pp. 50–51, 159–60). This broad definition can be seen as a strength, in that it provides the reader with a comprehensive view, but it also raises questions about the comparability of some very different tactics. Should covert assistance and “dirty tricks”—like those undertaken by the United States against Peron in Argentina (pp. 108–14)—be analyzed under the same theoretical lens as overt conditionality, such as the United States’ promise to hold a Four Power conference in order to support Konrad Adenauer in Germany (pp. 74–79)? This type of overt electoral conditionality has been used prominently by the European Union in its relations with postcommunist states (see Milada Vachudova, Europe Undivided, 2005). Levin’s account could be enriched by engaging with this literature, which positions conditionality along a spectrum of normative versus material tools of influence and finds, importantly, that effects differ across policy tools (for example, see Wade Jacoby, “Inspiration, Coalition and Substitution,” World Politics, 58, 2006; Judith Kelley, Ethnic Politics in Europe, 2004).

Levin’s book is a fine marriage of quantitative and qualitative analysis. Chapter 3 presents case studies of elections in West Germany in 1953, Guatemala in 1958, and Argentina in 1946—all targeted by US intervention); elections in Venezuela in 1958, the Philippines in 1965, and Greece in 1967, in which there was no US intervention, are explored in chapter 4. Chapters 5 and 6 present cross-national evidence on the causes and effects of electoral interventions, and chapter 7 makes clever use of public opinion surveys from Israel and West Germany to provide additional evidence that outside interference can influence voters’ opinions.

Taken together, these chapters support the theory of partisan electoral intervention that Levin advances with clarity and discipline. Interventions occur, he argues, when the intervenor perceives one political party in the target state as an existential threat and when the favored actor in the target state welcomes such intervention. Indeed, one of the more interesting findings revealed in the case studies is that the United States declined to meddle in elections when this intervention was unwanted by its target-state allies. Electoral interventions are generally effective, he argues, but especially so when the intervenor uses overt tactics (pp. 40–42).

The cross-national evidence presented in chapters 5 and 6 is important in that it demonstrates associations—spanning time and space—that are consistent with the theory. But there are some limitations to analyzing observational data on a phenomenon as complex as this one—limitations that Levin acknowledges (pp. 179–80). Perhaps most important is the issue of selection: Are great powers choosing to intervene in cases where their efforts are more likely to make a difference? The choice of overt versus covert methods is also strategic in ways not fully fleshed out in the book, in that one might expect overt methods to be chosen when the domestic public views the intervenor favorably and where, therefore, the risk of backlash is lower.

The qualitative evidence really shines in Meddling in the Ballot Box. The case studies address questions unanswered in the statistical analysis in exactly the way that a well-executed research design should. The case studies of Germany and Greece are particularly revealing, situated in a fascinating and nuanced discussion of the United States’ Cold War strategic priorities in Europe (chapters 3 and 4). I came away convinced by Levin’s characterization of how the United States perceived the various domestic political players in the “target” states.

The weight of evidence in Levin’s book centers on the Cold War period, but chapter 8 is devoted to the 2016 US election, focusing on Russia’s hacking and release of private emails. Russia’s social media influence campaign—the infamous “trolls,” “bots,” and Internet Research Agency (IRA)— receive less discussion here, and one comes away wondering whether the technological shift toward cybercampaigns has changed the game in fundamental ways. Intelligence reports indicate that Russia now views election interference as a low-cost and potentially high-reward tool of foreign influence, which suggests that the careful calculations of the past—in terms of selectively interfering only in cases of “existential threat”—may no longer apply. Interference may now be a tool wielded more indiscriminately—to wit, Russia’s meddling in many European elections. Also unanswered in Levin’s book are normative and conceptual questions related to the (il)legality of foreign election interference. What exactly is the nature of the beast? Is this a violation of international and domestic law, or do free speech protections prevail? These questions matter because they inform the steps that can be taken to address the problem. This is precisely where Jens David Ohlin’s book, Election Interference, picks up the thread.

Ohlin provides an analysis of how we should best characterize election interference under international law. He focuses specifically on the contemporary cybervariants of election meddling, using the 2016 US election as the case of interest. Although the heart of the book is devoted to legal analysis (chapters 2–4), chapter 1 begins with an excellent summary of the three forms of interference employed by Russia in 2016: the theft and release of private information through hacking, social media influence campaigns, and Russia’s infiltration of US advocacy organizations. For those of us too busy (or lazy) to read the full Mueller report, this chapter provides a thorough and satisfying lay of the land. Comparing the activities described here with Levin’s case studies from the 1950s–1960s, one is struck by the ways that the technology of election interference has evolved since the Cold War.

Ohlin critiques the conceptually muddled treatment of foreign election interference by policy makers and analysts. Commentators most often invoke two analogies—that of Russian interference as an “act of war” or as a “violation of sovereignty”—that, on examination, fall short in important ways. Ohlin carefully lays out these shortcomings in chapters 2 and 3. International case law and custom define acts of war as predicated on the existence of an armed conflict that produces death or physical destruction (pp. 50–55). And violations of sovereignty entail acts of coercion—implying force or threat—which is different from the manipulation of information employed by Russian election interference (pp. 78–85).

Instead, in chapter 4, Ohlin advances the claim that election interference is most usefully characterized as a violation of a people’s right of self-determination—a right with a long and storied status in international law, even if it has fallen out of fashion in recent decades because of its association with decolonization (p. 107). There are some clear advantages to the self-determination frame: like the sovereignty frame, it incorporates the intuitive idea of a boundary violation, but it also accounts for how the distortion of deliberations violates the peoples’ right to collectively determine their political fate (pp. 102–3).

Nevertheless, Ohlin’s effort to characterize foreign election interference in this way does raise some questions stemming from the fraught debate as to whether a right to self-determination implies a right to democracy (Thomas Franck, “The Emerging Right to Democratic Governance,” American Journal of International Law, 86, 1992). If it does not—as the weight of international legal opinion holds—then how can we characterize election interference as a violation of a people’s right to self-determination? Ohlin’s move is to argue that foreign electoral meddling violates self-determination only for those polities that are organized as electoral democracies (p. 97). But there would seem to be some challenges to applying this standard in practice. The contemporary international system is populated with many “hybrid” regimes where elections are held and competition is allowed, but the playing field is biased in myriad ways. How free and fair must an election be to be considered democratic? This is a question that political scientists have extensively grappled with, but it is not clear where Ohlin comes down on the issue. There is perhaps a circularity to Ohlin’s argument as well: democratic elections are a scope condition for the argument, but the very policies of interference in question seek to undermine the quality of elections.

These somewhat esoteric questions notwithstanding, Ohlin provides a thought-provoking and readable account of the legal issues surrounding contemporary election interference. The last four chapters of the book are devoted to policy recommendations for improved transparency regimes and more effective use of criminal prosecution. Those interested in the status of self-determination, free speech, and democracy under international law will find much to consider here.