Viet Hung Nguyen Cao
Viet-Hung Nguyen-Cao is a PhD candidate at the Graduate School of Political Science, Waseda University.
I study International Relations with a focus on international security, using survey experiments and text analysis. My current research interests include territorial disputes, public opinions and authoritarian politics.
For more information, see my CV here.
Research Experience
- 2026–present
- Research Associate
- Faculty of Political Science and Economics, Waseda University
Education
Waseda University | Tokyo, Japan
PhD in Political Science | Sept 2022 - present
MA in Political Science | Sept 2022
Tokyo International University | Saitama, Japan
BA in International Relations | March 2020
Publications
“‡” - manuscript under review
Peer-Reviewed Articles
Kudo, Yasuki, and Nguyen Cao, Viet Hung. 2025. “Does the US Really Embolden Its Allies? Evidence from a Survey Experiment in Japan.” Journal of Conflict Resolution 70 (4): 613-638.
Abstract: Do patrons’ signals of security commitments embolden junior partners? The literature on military alliances suggests that this might be the case: supportive gestures by patrons could motivate junior partners to adopt more aggressive postures in their own disputes than they would without such support. While the theoretical logic is compelling when considering states as unitary actors, it is less clear if this logic applies to the domestic public that may have differing interests from leaders. To complement this gap, we conducted a survey experiment in Japan, a close US ally with a territorial dispute with China, to explore the impact of US presidential signals on public support for adopting aggressive policies towards China. We find that US signals increase the credibility of US military intervention in territorial disputes; however no evidence of an emboldenment effect is found—public support for escalatory policies does not increase accordingly. Additionally, we find that US signals do not encourage the public to punish leaders backing down after announcing aggressive policies. These findings challenge the conventional understanding of an important effect of alliance politics.
Nguyen Cao, Viet Hung. 2025. “To War or Not to War: Backing down after a Fait Accompli in Japan.” Japanese Journal of Political Science 26 (1): 44–53.
A growing number of studies focus on how governments can manage audience costs when they want to back down from international crises. In line with previous studies, especially Kohama et al. (2024), this paper argues that the Japanese government can use a variety of reasons to justify its decisions to deescalate while minimizing the domestic audience costs. I found that governments can reduce audience costs by using several rhetorical devices, which reinforces the current understanding of audience costs. However, my design, which presented a fait accompli scenario by China against Japan, yielded significantly different results regarding certain aspects of audience costs compared to previous studies on the subject. Specifically, the results of this study indicate that the public might not value economic development following a fait accompli as highly as in less severe scenarios. The results also suggest that leaders might have a harder time backing down after a loss of territory, compared to other forms of provocation.
Working Papers
Does Neutrality Have a Price? Experimental Evidence from Japan and the Philippines (with Marvin H. Bernardo)
Do leaders in democratic states face domestic political costs for abandoning promises of neutrality and backing into conflicts? We investigate this question through pre-registered survey experiments in Japan and the Philippines (N=2,398), testing whether Type II audience costs—the punishment leaders face for policy reversals toward intervention—operate in US allies. Using realistic Taiwan contingency scenarios, we find that contrary to theoretical predictions, leaders in both countries do not face significant audience costs for abandoning neutrality to support US military action. However, exploratory analysis reveals a powerful moderator: public perceptions of alliance consequences. When respondents believe backing into conflict strengthens their country’s alliance with the United States, Type II audience costs disappear entirely—and in the Philippines, even reverse, with publics supporting leaders who break neutrality promises. This moderation effect is stronger in the Philippines than Japan, reflecting differences in alliance insecurity. Our findings suggest Type II audience costs operate conditionally: in asymmetric alliance relationships, alliance maintenance concerns can override consistency preferences. These results have important implications for audience costs theory, alliance burden-sharing dynamics, and Taiwan contingency planning in the Indo-Pacific.
Threats, Assurances, and Public Support for Military Retaliation after a Fait Accompli‡
Tie hands or not tie hands: Decoding responses of weaker claimants in the South China Sea (with Marvin H. Bernardo and Aaron Denison Deivasagayam)
Elite-Led Caution: The Elite-Public Gap in Attitudes Toward China and the United States in Southeast Asia‡
Whose claims, whose norm: Vietnam, the Philippines, and great-power territorial violations‡
Examining Vietnamese attitudes toward China: Moving beyond the ‘anti-China’ framing‡ (with Phan Xuan Dung and Richard Turscsanyi)
Other Publications
“Does Ideology Matter in Vietnam’s Foreign Policy?” The Diplomat.