Although the American foreign basing network is a central aspect of international security politics, there is a lot we do not know about it. Michael A. Allen, Michael E. Flynn, Carla Martinez Machain, and Andrew Stravers have written an important contribution to increasing our understanding of the dynamics of US foreign military presences. Through a survey of more than 42,000 individuals in 14 states that host US military bases, the authors generated a significant dataset for thinking about the relationship between US military bases and the societies in which they are embedded. Such a comprehensive effort to collect cross-national data is a real step forward in comprehending the drivers of base politics at an individual level. Allen and coauthors rightly frame their contribution as filling a significant gap in how we think about base dynamics. Instead of a macro-level analysis, they are interested in understanding the microfoundations of US hegemony; that is, the interactions at the level of individuals that account for the ability of the United States to station troops in hundreds of bases all over the world. Previous work mostly focused on elite politics and the bargains underpinning basing relationships, or if quantitative, they relied on highly aggregated data. These works provide crucial insights, but they tend to make assumptions about the societal support that basing relationships may or may not have and therefore arguably miss important dynamics.

Allen and coauthors justify their approach by pointing to what they call the emerging “domain of competitive consent.” Given a general trend toward the increased political participation of publics in policy making, a development mediated in part by the spread of new communications technologies, states—whether liberal democratic or various shades of authoritarian—increasingly rely on the consent of their publics when accepting the presence of a foreign military. Interactions between the foreign military and the host population and how those interactions shape the perceptions of the military presence therefore become critically important in assessing the stability of basing relationships. This emerging factor in basing dynamics is particularly important given the rise of other powers like China that have an expressed interest in expanding their strategic footprint. China has already established a formal, long-term military base in Djibouti, and it is possible that other states might soon serve as hosts to Chinese bases.

As a result, the United States finds itself in a competitive environment for securing military access in which the consent of host populations is ever more central. Unfortunate events that aggravate relations with host populations or result in sustained protests put pressure on host governments to either extract more concessions from the United States or to ask the United States to leave altogether. Conversely, good relations with host populations help the US presence become an accepted feature of everyday politics. This prospect of a more competitive basing space in the near future aligns with my own thinking on the matter, and it ties this work closely to conversations about the sources of international order. Foreign military basing is the backbone of the American-led order, and this order is becoming more and more reliant on countless personal interactions that ultimately provide the political space for basing relationships to exist in the first place.

Through their large sample and sophisticated methodology, the authors tease out some very interesting findings. First, a general finding that validates their approach is that individual experiences with a US military presence have an important effect beyond environmental factors (such as GDP, population, troop level, etc.) on how the presence is perceived. Second, contact between US military personnel and the local population, although it carries with it the inevitability of some negative interactions, has an overall positive impact on the perceptions of the local population of the US presence. In particular, contact with the US military appears to moderate the effect of negative interactions, such as having experienced crime at the hands of US military personnel. This has two important policy implications. A particularly important one is that the usual practice of base commanders restricting troops to base after incidents with the local population—and indeed the progressive isolation of bases from host populations that the United States has pursued over the years to reduce friction—may actually make the problem worse by taking off the table the positive interactions that mediate negative ones. Second, given the importance of interpersonal interaction, the US military should invest in personnel who focus on developing relationships with the local community.

Allen and coauthors also conducted interviews with a broad range of actors, including policy makers, US troops, and anti-base activists. These interviews are particularly valuable for adding depth to their survey findings. For example, the authors find that not only is the reduction in contact through isolation of the base from the local population probably a bad thing on balance but it also turns out that this isolation allows rumors about what might be happening at the base to take root in the area. Thus, continued contact with the host population not only provides opportunities for positive interactions but also the increased transparency that this kind of interaction provides helps dispel rumors and familiarize the host populations with the activities of the base.

The sheer scale of the data that the authors collected, their careful analysis of it, and the extensive interviews they conducted provide invaluable insight into basing dynamics. Their work is directly applicable to policy questions and is also relevant for IR scholars interested in questions of American hegemony, empire, and the international order more generally. One finding that would benefit from more clarity, however, concerns the recommendation for the nature of the US military presence. The authors argue that a larger military presence is linked with more protests, suggesting that a sizable presence is problematic. At the same time, they recommend against the smaller presences recently pursued by the United States that substitute capital for labor, because “many negative costs will remain while some benefits are lost” (p. 188). One way to perhaps square these arguments is to look more closely at the nature and aims of protests. Allen and coauthors carefully link personal experiences with the propensity to get involved with protest actions, but this is a rough measure. Protests do not necessarily entail demands for a base to be removed or dissatisfaction with the presence as such; more often, they may have as their goal the mitigation of environmental damage or crime. In fact, as Claudia J. Kim and Taylor C. Boas note in their article “Activist Disconnect: Social Movements, Public Opinion, and U.S. Military Bases in East Asia” (Armed Forces & Society 46 [4], 2020), anti-base protests focused on issues of national sovereignty resonate weakly with publics compared to those focused on social and environmental harms. As such, protests might not express a desire for an end to the basing relationship but may rather speak to the integration of the base into contentious domestic politics.

There is a lot of work to be done in extending the analysis of protests as the link between individual experience and possible policy change. This issue, however, goes beyond the survey that Allen and coauthors conducted, so it is really a matter for further research. As it is, they bring so much data to bear on important issues concerning US basing that we will be in debt to their research findings for a long time to come.