What international law obligations restrict the U.S. from denationalizing people with dual nationality?
Executive summary
International law does not create an absolute ban on a State stripping citizenship from dual nationals, but it bars “arbitrary” denationalization and imposes strong constraints aimed at preventing statelessness and human-rights abuses (see academic analysis at the University of Chicago Journal of International Law) [1]. U.S. practice and current federal materials treat dual nationality as accepted, and a new proposal—the Exclusive Citizenship Act of 2025—would attempt to force choice within 12 months but has not become law and would confront constitutional and international-law limits [2] [3] [4].
1. International-law guardrails: “no outright ban, but no arbitrariness”
International commentators conclude there is no blanket prohibition on revoking nationality of a dual national, yet international law prohibits arbitrary denationalization and creates substantive constraints states must respect [1]. The Chicago Journal of International Law summary explains that while denationalization of someone who holds another nationality can be legal in principle, international human-rights norms restrict arbitrary or discriminatory revocations and raise problems when denationalization is used as a broad counterterrorism tool [1].
2. The problem of statelessness: treaties and norms that shape state choices
Available sources note conventions and norms aimed at reducing statelessness may limit use of denationalization, though the sources emphasize ambiguity about the full scope of protections [1]. The academic piece flags that conventions addressing statelessness and nationality as a fundamental right “may prohibit denationalization as a tool of state counterterrorism policy,” and that states seeking to revoke nationality must weigh those legal and normative consequences [1].
3. U.S. domestic practice and policy: longstanding tolerance of dual nationality
U.S. law and practice has long accommodated dual nationality; State Department guidance calls dual nationality a “natural consequence” of overlapping national laws and U.S. practice does not currently require people to choose one citizenship [5] [6]. The State Department Foreign Affairs Manual recognizes that persons can hold rights and responsibilities in two countries, and recent overviews reiterate that the U.S. effectively allows nationals to acquire new nationality while remaining U.S. nationals [5] [7].
4. Legislative push and friction: the Exclusive Citizenship Act of 2025
Several news outlets report Senator Bernie Moreno’s Exclusive Citizenship Act would prohibit simultaneous U.S. and foreign citizenships, require dual citizens to choose within about a year, create federal recordkeeping and could lead to automatic loss of U.S. nationality for noncompliance [2] [3] [4]. Coverage also stresses the bill has not been enacted and would face legal challenges; analysts point out it removes the traditional requirement that loss of citizenship be voluntary and intentional—a constitutional protection under U.S. law according to commentators cited in reporting [2] [8].
5. Legal and constitutional fault lines the U.S. would face
Reporting and expert commentary cited in the coverage say the proposed law’s automatic or “deemed” expatriation model would conflict with constitutional protections requiring voluntariness and intent for loss of citizenship and would yield severe tax and administrative consequences for individuals labeled as expatriates [2]. The articles suggest that beyond domestic constitutional challenges, implementation would collide with international-law limits on arbitrary denationalization and obligations to avoid creating stateless persons [2] [1].
6. Competing perspectives and hidden agendas
Supporters of the bill frame it as enforcing “sole and exclusive allegiance” and national-security clarity; critics—including legal analysts and tax advisers—argue the proposal’s real-world impact would be punitive, administratively fraught, and likely unconstitutional [3] [2] [8]. Some coverage emphasizes political signaling: the proposal fits a broader political agenda on immigration and allegiance rather than reflecting an imminent, administrable policy shift [4] [3].
7. What the reporting does not settle
Available sources do not lay out a definitive catalogue of which specific international treaties or articles would categorically block the U.S. from denationalizing dual nationals, nor do they provide court rulings that resolve every cross-border legal question about arbitrariness or statelessness in this precise context—those details are “not found in current reporting” [1] [5]. The academic commentary, however, makes clear that international-law principles against arbitrary revocations and against creating statelessness will be central in any legal contest [1].
8. Bottom line for policymakers and citizens
If Congress were to try to strip U.S. nationality from large groups of dual nationals, the move would immediately trigger constitutional challenges, international-law scrutiny about arbitrariness and statelessness, and significant administrative and tax complications—issues emphasized across news and expert commentary [2] [1] [8]. The Exclusive Citizenship Act of 2025 illustrates the political momentum for change but, as reporting stresses, the bill is unpassed and would confront deep legal and normative headwinds [3] [4].