Promises under Pressure: Statements of Reassurance in US Alliances

Abstract

The United States frequently reassures allies of its protection by stationing troops abroad, visiting allied countries, and making public statements. Yet the causes of reassurance in asymmetric alliances—those between a great power patron and its weaker allies—are understudied in the academic literature. Indeed, many scholars argue that reassurance can be counterproductive as it invites allies to free ride or provoke their adversaries, knowing that they have their patron's support. Despite the drawbacks, I argue that the United States use reassurance to discourage their allies from seeking outside options and reducing their dependence on the alliance. Patrons such as the United States thus face a dilemma wherein they trade-off between withholding reassurance for short-term leverage and using reassurance to preserve their long-term influence. I test the theory using a new cross-national dataset of US. statements of reassurance from 1950 to 2010, and the results provide stronger support for my hypotheses than for the competing explanations of deterrence, strength from desperation, and shared preferences. The findings have implications for understanding how great powers manage their alliances, and suggest a pathway through which weaker states can shape great powers’ foreign commitments.

Keeping Your Friends Close, but Acquaintances Closer: Why Weakly Allied States Make Committed Coalition Partners

“…We include a measure of the Composite Index of National Capabilities (CINC) as well as economic measures of logged GDP and logged GDP per capita in line with the collective action hypothesis that the highest contributions should come from states with larger military and economic capacity because alliances are public goods (Olson and Zeckhauser 1966; Singer, Bremer, and Stuckey 1972). Aggregated capabilities and economic capacity could also influence unrealized alliance potential because national capability impacts the ability of a potential partner to deter (Walt 1987), because asymmetrical alliances are longer lasting (Morrow 1991; Blankenship 2018), and because economic capacity impacts how much a state can contribute and whether they seek economic payoffs from troops contributions (Bove and Elia 2011; Henke 2019a).…”

Four Costly Signaling Mechanisms

“…Examples include the recent work on leader-specific reputation (e.g., Lupton 2018;McManus 2018;Wu and Wolford 2018), covert communication (e.g., Carson and Yarhi-Milo 2017;McManus and Yarhi-Milo 2017), alliance commitments (e.g., Fang, Johnson, and Leeds 2014), cyberwarfare (e.g., Gartzke and Lindsay 2017), and fait accompli (e.g., Altman 2017;Tarar 2016). Scholars have also applied costly signaling to better understand the conditions that sustain peace after civil wars (e.g., Hartzell and Hoddie 2007;Mattes and Savun 2009;Mattes and Vonnahme 2010; see also Reiter 2009), the implications of trade interdependence (e.g., Gartzke and Westerwinter 2016), the dynamics of trust and reassurance (e.g., Acharya and Ramsay 2013;Blankenship 2020;Chan 2012;Haynes and Yoder 2020;Kydd 2005;Kydd and McManus 2017), and the signaling functions of international institutions such as the International Monetary Fund and United Nations (e.g., Dai, Snidal, and Sampson 2017;Fang 2008;Simmons 2000;Tago and Ikeda 2015;Voeten 2005). Scholars have also applied costly signaling across the social sciences, from economics and sociology to anthropology and archaeology (reviewed in Bliege Bird and Smith 2005;Gambetta 2009;Quinn 2019;Riley 2001).…”

The US–South Korea alliance: How the patron benefits from the protégé

“…Of course, patrons and protégés do not fully know each other's commitment levels or prospects for future defection (Blankenship, 2020). Patrons want reliable partners that sacrifice their own interests for the patron's security interests.…”

“…The rivalrous relationship confronting a patron also affects a protégé's level of independence. Since protégés fear abandonment, patrons offer public displays of support to consolidate the alliance and discourage defection (Blankenship, 2020). For example, military exercises and basing provide a signal of commitment from patron to protégé.…”

“…In the case of the US-South Korea alliance, the Trump administration continuously threatened US commitment to the pact, referring to a possible withdrawal of US forces from South Korea and asserting that the protégé should agree to a significant increase in cost-sharing. US allies could seek options outside the alliance and reduce their dependence on the alliance with the US (Blankenship, 2020).…”