Following Russia's 2022 invasion of Ukraine, NATO expanded its Enhanced Forward Presence initiative to include four new locations in Central and Eastern Europe. The reception of these foreign troops has been mixed among host countries, with local figures and groups in some nations opposing the deployment. While a growing body of research examines how anti-NATO political actors exploit the presence of multinational battalion battle groups for political gain, the factors shaping public opinion on this issue remain understudied. This paper investigates how individuals' perceptions of personal and national vulnerability during a hypothetical global conflict influence their attitudes toward hosting foreign NATO troops. Additionally, it examines whether these perceptions affect pro-Western and non-pro-Western individuals differently. Using survey data collected in May 2025, I analyze responses from Slovakia—a host nation with a geopolitically polarized society—and the Czech Republic—a non-host nation with a predominantly pro-Western orientation. I expect to find that heightened perceptions of vulnerability increase support for hosting NATO troops, particularly among pro-Western respondents, while non-pro-Western individuals may show weaker or even negative associations between perceived vulnerability and support for foreign troop presence. These findings would contribute to our understanding of how threat perceptions shape public attitudes toward collective defense arrangements in diverse political contexts.

How do allied force deployments shape public preferences for defense spending in frontline NATO states? This study examines defense spending preferences in Lithuania—a setting where baseline support is widely understood to be strong—in response to changes in NATO force posture. We investigate how deployment commitments by NATO's largest allies influence support for defense spending in smaller frontline allies facing heightened military risk since Russia's 2022 invasion of Ukraine. Our study moves beyond the typical U.S.-centric lens in alliance research by examining the interplay between deployments from both the United States and Germany, NATO's two largest contributors. Lithuania's recent bilateral agreement to permanently station a German brigade by 2027 provides a unique context to test theories of burden-sharing, abandonment, and reciprocity within NATO. Given Lithuania's high baseline support for defense policy (44.5% consider increasing defense spending the country's top priority), evidence of preferences for decreased defense expenditure would strongly indicate free-riding dynamics. We will field a pre-registered online survey experiment (N=3,200) on a nationally representative sample of Lithuanian adults. Respondents will be randomly assigned to one of four vignettes: (1) a status-quo control, (2) U.S. troop reduction from 1,000 to 150 personnel, (3) German troop increase by 1,000 armored forces, or (4) combined U.S. drawdown plus German increase. Our primary outcome measures support for national defense spending. Secondary outcomes include a budget-allocation trade-off using Best-Worst Scaling methodology and perceptions of personal safety from foreign threats. We test five competing theoretical mechanisms: abandonment-rally effects predicting U.S. deployments as uniquely credible (H1), capability-based substitution where allied forces are fungible (H2), reciprocity norms that encourage matching allied contributions (H3), loss-salience from prospect theory suggesting asymmetric responses to gains versus losses (H4), and entrapment concerns where increased allied presence heightens target risk (H5). We pre-specify mediators to assess each mechanism, including perceived Russian threat, NATO readiness, fairness norms, loss salience, and target externalities. The findings will have important implications for understanding alliance dynamics, particularly regarding burden-sharing and the potential for alliance regionalization as European allies may need to compensate for uncertain U.S. commitments. Lithuania's strategic exposure and sensitivity to alliance signals make it an ideal setting to observe how NATO's evolving force posture shapes domestic defense preferences in frontline states. (with co-authors)

Debates about military expenditures and burden-sharing in NATO have focused primarily on realized military spending in both aggregate and disaggregated forms. However, the existing literature has not examined the gap between promised military expenditures—as reported in NATO defence expenditure reports at the beginning of each year—and actual expenditures reported the following year. Using fixed-effects panel regression analysis for 2005–2024, a period encompassing the era of the 2% GDP target, we analyze both overall military spending and separate expenditure subcategories. Our results indicate that the gap between promises and outcomes cannot be explained by differences between expected and realized economic growth. Rather, states that planned to spend less than 2% of GDP were more likely to exceed their planned spending, while states that planned to spend above 2% tended to underspend relative to their commitments. This finding remains robust across a range of control variables. We argue that these results support the proposition that international institutions can shape state behavior, demonstrating that the 2% target functions as a focal point that influences actual military expenditure decisions.