What Forty-Two Countries Teach Us About Belonging: A Wealth Actually Field Note on Citizenship and Sovereignty
I spend most of my professional life helping families figure out who gets what, and under what conditions, across generations. Citizenship law turns out to be the same question asked at the level of the nation-state instead of the family trust. Who belongs. What you owe in exchange for belonging. And what happens to the people who show up later and want in.
A few months back I came across a piece of academic work comparing how China frames citizenship against how the United States does it. The article, written by Zhao, Wang, and Guo for the journal Citizenship Studies, laid out seven dimensions worth comparing: how a country decides who is born into membership, what it takes to earn membership as an adult, whether the whole enterprise is oriented around the individual or the collective, how the state handles religion, whether everyone is treated equally under the law, what a new citizen swears loyalty to, and what channels exist for citizens to push back against their own government.
That’s a good framework. So I decided to run it against forty of the other major economies on the planet, mostly the OECD, plus India, Russia, and Nigeria, and see what fell out. What follows is the plain-language version of that research, without the footnote-per-sentence density of the working matrix. Every claim below traces back to an actual constitution, statute, or gazette entry, and I have kept the citations at the end of each section rather than breaking up the prose with them.
The short version: birthright citizenship is dying almost everywhere except the Americas, the naturalization oath is the single sharpest fault line separating one country’s idea of citizenship from another’s, and a country’s wealth or its neighborhood tells you almost nothing about how it handles the separation of church and state. Read on for the long version.
China and the United States: Two Theories of the Person
Start where the original research started. China’s approach to citizenship, at least as Zhao, Wang, and Guo describe it, runs on a culturalist and ethnic tradition rooted in the old Hua-Yi distinction between the civilized center and the outsider periphery. That framework surfaced publicly in 2020, when a proposed permanent-residency law triggered a domestic backlash with racial overtones that the authors read as evidence the old hierarchy is still doing quiet work under the surface. Chinese personhood, in this telling, is relational rather than individual. You are a citizen the way you are a son or a daughter: embedded in obligations to family and to the nation-state, informed by Confucian, Daoist, and Buddhist habits of self-cultivation rather than by a Lockean theory of natural rights. The state, in turn, treats the moral and spiritual life of its citizens as its business. There is no meaningful line between public authority and private conscience. And loyalty is not a legal abstraction. It is bound to the party-state’s own narrative of what a citizen should be, a narrative that has only intensified under Xi-era campaigns to define the “ideal citizen.” When Chinese citizens want to change something, the research describes a preference for grassroots negotiation over open confrontation. Work the system quietly rather than march on it.
The American theory of citizenship could hardly be more different, and the difference is written into the plainest sentence in the Fourteenth Amendment: all persons born or naturalized in the United States, and subject to its jurisdiction, are citizens. Full stop. No ethnicity test, no cultural test. The Supreme Court made the point explicit in 1898 in United States v. Wong Kim Ark, when it confirmed that birth on American soil confers citizenship regardless of the parents’ race or national origin. The naturalization statute backs this up with a five-year residency requirement, good moral character, and attachment to the Constitution, which is a fairly thin bar compared to what you’ll see elsewhere in this survey. Individual rights, not collective obligation, sit at the center of the American constitutional order, expressed through the privileges, immunities, and due process language of the same Fourteenth Amendment. The First Amendment keeps the state out of the religion business in both directions, establishment and free exercise. The naturalization oath asks new citizens to support and defend the Constitution and the laws, nothing more elaborate than that. And when Americans want to change something, they have a constitutional green light to say so, assemble about it, and petition the government directly.
Two nations, two philosophies of what a citizen actually is. China’s is thick with obligation and cultural inheritance. America’s is comparatively thin and procedural, oriented around what the individual is owed rather than what the individual owes the collective. Keep that distinction in mind, because it recurs, in various disguises, across the other forty countries.
Sources: Zhao, Wang & Guo, Citizenship Studies (2023); Fourteenth Amendment; United States v. Wong Kim Ark, 169 U.S. 649 (1898); 8 U.S.C. §1427; 8 CFR Part 316; First Amendment.
The British Isles and Western Europe: Old Crowns, New Tests
The United Kingdom still runs citizenship the way you would expect of a country without a written constitution: through statute, layered and amended over decades rather than declared in a single founding document. The British Nationality Act gives you conditional birthright citizenship plus descent, a five-year residency requirement for naturalization, a language test, and something called the “Life in the UK” test, which is exactly what it sounds like. New citizens pledge allegiance not to a document but to a person, the monarch, alongside a loyalty pledge to the country itself. It is one of the few remaining places in the developed world where citizenship still runs through a crown rather than a constitution.
Ireland’s constitution is more philosophically interesting than most people realize. It explicitly blends individual rights with a constitutionally protected notion of the family as an organic unit, and it imposes on citizens an express duty of fidelity to the nation. Naturalization takes five years of what the statute calls “reckonable residence” and requires good character, standard enough. But Ireland has no textual right to petition the government, an absence that will come up again and again in this survey. Speech and assembly, yes. The right to formally petition, no.
France runs on jus sanguinis, citizenship by descent, layered with a version of jus soli that only fully vests when a French-born child of foreign parents reaches the age of majority and has lived in France continuously. Naturalization asks for five years of residence plus what the Civil Code calls “assimilation,” a formal commitment to French values that goes beyond simple language proficiency. France has no naturalization oath at all. Instead, new citizens sign a charter of rights and duties, a document rather than a spoken pledge. The country’s commitment to laïcité, the strict separation of religion from public life, is both statutory and constitutional, tracing back to the 1905 law and reinforced in the current constitution’s first article. And oddly for a country this committed to civic participation, the constitutional right to petition exists only at the local level. There is no general national petition clause.
Germany’s Basic Law centers everything on human dignity, a phrase that appears in the document’s first article and colors everything that follows, including a “militant democracy” doctrine that allows the state to defend itself against anti-democratic movements even when those movements claim to be exercising constitutional rights. Naturalization requires five years, a B1 German-language certificate, and a civics test, standard by continental European standards. Germany has no state church, a settled matter since the Basic Law’s Article 140 incorporated the older Weimar-era religious-liberty provisions. New citizens pledge loyalty not to a monarch or a nation in the abstract but to the Basic Law itself, which tells you something about how seriously postwar Germany takes its own constitutional order as the anchor of citizenship.
The Netherlands, Belgium, and Luxembourg round out this region, and each has its own quirk. The Dutch naturalization law requires five years and an integration test, but researchers could not locate an express church-state separation clause in the Dutch constitution at all, an absence worth flagging given how secular the country’s public life actually is. Belgium requires five years plus language and economic integration, and its constitution recognizes religious “cults” with state-paid clergy, a formal arrangement that sits oddly next to the country’s reputation for progressive secularism. Neither the Netherlands nor Belgium requires any naturalization oath. Luxembourg, notably, only wrote church-state separation into its constitution in 2023, making it one of the most recent countries in this survey to formalize that principle in writing.
Sources: British Nationality Act 1981; Bunreacht na hÉireann; Irish Nationality and Citizenship Act 1956; French Code civil; French Constitution, Art.1; German Basic Law, Art.1; StAG §10; Dutch Rijkswet op het Nederlanderschap; Belgian Code de la nationalité belge; Luxembourg Constitution, Art.120.
Alpine, Southern, and Atlantic Europe: The Ten-Year Club
Switzerland, Austria, Italy, and Spain form a rough cluster of countries that all demand roughly a decade of residence before naturalization, considerably longer than the five-year norm further north. Switzerland’s system is genuinely unusual: citizenship runs through three tiers, commune, canton, and federation, all at once, and the federal constitution’s preamble still invokes “Almighty God,” a holdover from an earlier era that coexists with a 2009 constitutional amendment banning the construction of minarets. There is no naturalization oath anywhere in Swiss federal law, a striking omission for a country otherwise known for procedural formality.
Austria requires ten years of residence, five if you’re already settled, plus a language and civics test under the Integration Act, and new citizens swear a Gelöbnis, a pledge to the Republic and to European democratic values specifically, one of the few oaths in this survey that names a supranational commitment rather than just the nation itself. Italy sits at ten years generally, with a tiered reduction for special cases, and its constitution embeds a formal concordat with the Catholic Church even though the country has no official state religion. Spain also asks for ten years, cut to two for applicants from Ibero-America or of Sephardic Jewish descent, a historical carve-out tracing back to the expulsion of Spain’s Jewish population in 1492. Spanish naturalization still requires an oath to the King personally, one of only four countries in this entire survey where a monarch, rather than a constitution or a nation in the abstract, is the object of a new citizen’s pledge.
Portugal, Greece, and Iceland complete this group, and Portugal is worth watching closely because its law just changed. As of May 2026, Portugal lengthened its residency requirement from a flat five years to seven years for citizens of Portuguese-speaking or EU countries and ten years for everyone else, and it replaced its old oath with a “solemn declaration” of adherence to democratic rule of law. That is a meaningfully more restrictive regime than existed even two years ago, and it runs against the general European trend toward easier naturalization. Greece asks for seven years generally, waives residency entirely for applicants of ethnic Greek descent, and treats its Eastern Orthodox faith as the constitutional “prevailing religion,” a designation that coexists with an outright ban on religious proselytism. Citizenship in Greece is also constitutively tied to the oath itself: legally speaking, you are not a citizen until you swear it. Iceland has no naturalization oath, but it does maintain an established Evangelical Lutheran state church written directly into its constitution, a fact that surprises people who think of Iceland as a thoroughly secular, socially liberal state.
Sources: Swiss Federal Constitution, Art.37; Austrian Staatsbürgerschaftsgesetz §21; Italian Law 91/1992; Spanish Código Civil, Art.22-23; Portuguese Lei Orgânica 1/2026; Greek Nationality Code; Icelandic Constitution, Art.62.
The Nordics and Central Europe: Disestablishment Meets Its Exceptions
Sweden, Norway, Denmark, and Finland get filed together in most people’s minds as a single Scandinavian model, but their church-state arrangements diverge sharply. Sweden disestablished its church in 2000 and has no naturalization oath at all. Norway and Denmark, by contrast, still maintain established Evangelical Lutheran state churches written into their constitutions, and Denmark’s monarch is constitutionally required to belong to the church. Finland occupies a middle position: no formal establishment clause, but the Lutheran Church retains a distinct constitutional status that ordinary religious organizations do not have. Naturalization residency across this group runs from eight to nine years, with Norway and Finland both requiring a formal citizenship test on top of language proficiency. None of the four requires a legally binding oath. Norway’s citizenship ceremony includes a pledge, but government guidance is explicit that it carries no legal effect. It’s theater, not law.
Poland, the Czech Republic, and Slovakia present a different pattern. All three explicitly declare, in their post-communist constitutions, that the state is not attached to any ideology or religion, a specific and deliberate reaction to the ideological state apparatus these countries lived under before 1989. Poland’s naturalization law offers a fast three-year route for applicants with a documented connection to Poland, alongside a slower discretionary presidential route for everyone else. The Czech Republic and Slovakia both treat their naturalization oaths as constitutive: legally, citizenship does not vest until the pledge to the Republic, its constitution, and its laws is actually sworn.
Sources: Swedish Instrument of Government, Ch.8; Norwegian Constitution, Art.16; Danish Grundlov §§4, 6; Finnish Constitution §§11, 76; Polish Citizenship Act 2009; Czech Citizenship Act §27; Slovak Citizenship Act §8a.
The Baltics, Southeastern Europe, Türkiye, and Israel: Where Descent Becomes Ideology
This group produces some of the most philosophically loaded citizenship regimes in the entire survey. Estonia, Latvia, Lithuania, and Slovenia all run on straightforward jus sanguinis, citizenship by descent, with residency requirements for naturalization ranging from eight to ten years. Latvia’s naturalization oath is unusual in naming a specific language, not just the state or the constitution, as an object of allegiance: new citizens pledge loyalty to the state, the constitution, independence, and the Latvian language by name.
Hungary and Türkiye both build an unusually thick relationship between citizenship and national or cultural identity directly into their constitutional text. Hungary’s Fundamental Law offers naturalization with zero residency requirement at all for applicants who can establish ethnic Hungarian descent, an extraordinarily generous carve-out compared to the eight years required of everyone else. The same document formally separates church and state while simultaneously imposing a constitutional duty on the state to protect “Christian culture,” a combination that reads as contradictory until you understand it as two different, deliberately coexisting commitments. Türkiye’s constitution enshrines what it calls “militant secularism” while also funding a state Directorate of Religious Affairs, the Diyanet, which manages mosques and religious education nationwide. Turkish citizenship requires no oath whatsoever. Loyalty appears in Turkish law only as a standard for revoking citizenship, never as an affirmative pledge required to obtain it.
Israel is the outlier that proves how much this framework can bend before it breaks. There is no general jus soli in Israeli law. Citizenship instead runs primarily through the Law of Return, which grants automatic citizenship to Jewish immigrants as a matter of peoplehood rather than territorial birth, and religious descent or conversion functions as the actual constitutive test for that path. Israel has no written church-state separation clause of any kind, and its Basic Laws contain no general textual equality clause and no protection for speech, assembly, or petition. All of that constitutional territory is instead filled in by judicial interpretation built up over decades, rather than by text you can point to and read. It is the thinnest textual foundation for basic civil liberties of any developed democracy in this survey, resting almost entirely on case law rather than codified guarantee.
Sources: Estonian Constitution §8; Latvian Citizenship Law s.18; Hungarian Fundamental Law, Art. G and Art. R(4); Turkish Constitution, Arts.2, 136; Israeli Law of Return; Israeli Nationality Law §5; Basic Law: The Knesset §7a.
The Americas and Oceania: The Last Refuge of Birthright Citizenship
If you want to find a country that still treats unrestricted birthright citizenship as an unremarkable baseline rather than a contested policy question, the Americas are where you look. Canada, Mexico, Chile, Colombia, and Costa Rica all retain meaningful jus soli, birth-based citizenship, largely without the conditions and carve-outs that have crept into European and Asian law over the past several decades.
Canada’s system is close to unconditional: born on Canadian soil, you’re a citizen, full stop, subject to a narrow set of exceptions for children of foreign diplomats. Naturalization takes three years, and the oath, notably, is directed at the reigning monarch personally, plus the laws and constitution, one of only four monarch-directed oaths in this survey. Mexico pairs equally robust birthright citizenship with an unusually forceful constitutional separation of church and state, a legacy of the country’s revolutionary-era conflicts with the Catholic Church’s institutional power. Chile treats birthright citizenship as the primary rule and citizenship by descent as conditional rather than the reverse, an inversion of the European pattern, and it requires no naturalization oath at all, asking instead for a formal renunciation of prior citizenship. Colombia blends conditional birthright citizenship with descent and layers on nine separately enumerated constitutional duties of citizenship, a level of textual specificity about civic obligation that most Western constitutions don’t bother with.
Costa Rica deserves particular attention because it is the only country in the entire Americas with an official state religion. Roman Catholicism holds that constitutional status, a genuinely unusual arrangement for a hemisphere otherwise defined by strict separation, most visibly in Mexico’s own constitution.
Australia and New Zealand both abandoned unconditional birthright citizenship within living memory, Australia in 1986 and New Zealand in 2006, converging toward the same parental-status model that already dominates Europe and Asia. Australia’s constitutional structure is genuinely spare: the country has no bill of rights, and researchers could identify only five explicit individual rights anywhere in the document. There is no general constitutional equality clause either, only a narrow provision barring discrimination based on state residency. Whatever civil-liberties protection Australians enjoy beyond that text comes from judicial doctrine, principally an implied freedom of political communication that the courts have read into the structure of the constitution rather than found written in it. New Zealand runs its rights regime through an ordinary statute, the Bill of Rights Act of 1990, which is not entrenched as supreme law and could in principle be amended by ordinary legislative majority, a meaningfully weaker form of constitutional protection than exists in most of the rest of this survey. New Zealand’s naturalization oath, notably, is still directed at the Sovereign personally, matching Canada’s monarchical framing.
Sources: Canadian Citizenship Act s.3; Mexican Constitution, Art.130; Chilean Constitution, Art.10; Colombian Constitution, Arts.1, 95; Costa Rican Constitution, Art.75; Australian Constitution s.117; Australian Human Rights Commission; New Zealand Bill of Rights Act 1990; New Zealand Citizenship Act 1977, Sch.1.
East Asia, India, Russia, and Nigeria: Descent, Duty, and the Longest Wait in the World
Japan and South Korea both run on pure jus sanguinis with no meaningful birthright exception, and both impose a discretionary, fully merit-based naturalization process after five years of residence. Japan’s constitution frames individuals as entitled to respect, in the plain language of Article 13, but immediately qualifies that respect by reference to the “public welfare,” a phrase that gives the state considerable latitude to constrain individual rights in the name of collective interest. Japan has no statutory naturalization oath, relying instead on a negative loyalty screen, essentially a background check for disqualifying conduct, rather than an affirmative pledge. South Korea takes the opposite approach: citizenship legally vests only at the moment the oath is sworn, making the pledge itself the constitutive legal act rather than a ceremonial afterthought, though the exact wording is left to presidential decree and isn’t published in the underlying statute.
India’s story is one of retreat. The country ran on strong, largely unconditional birthright citizenship from 1950 to 1987, then narrowed sharply toward a descent-dominant model. Ordinary naturalization now takes roughly twelve years, among the longest ordinary residency requirements in this entire survey, but the 2019 Citizenship Amendment Act carved out a five-year fast track for six specifically named religious minorities arriving from Afghanistan, Bangladesh, and Pakistan, a provision that has been the subject of considerable domestic political controversy since its passage. India’s constitution declares the country “SECULAR” in its preamble, a word added by a 1976 amendment, while its Fundamental Duties clause imposes eleven distinct civic obligations on every citizen, a level of specificity about what citizens owe the state that goes well beyond anything in the American or British tradition.
Russia’s citizenship law is overwhelmingly descent-based, with birthright citizenship reserved narrowly for statelessness-prevention cases. Naturalization requires five years of permanent residence, a Russian-language test, and an examination on Russian history and legislation. The oath itself is, by a wide margin, the most ideologically dense of any researched in this survey: new citizens pledge loyalty not just to the constitution and laws but to Russian culture, history, and tradition by name, a formulation with no real analogue anywhere else in this study. A 2020 constitutional amendment added language committing the state to “faith in God” and historical continuity, layered on top of a document that otherwise describes Russia as secular.
Nigeria closes out the survey, and it does so with the single longest ordinary naturalization residency requirement researched anywhere: fifteen continuous years, nearly triple the informal five-year norm that governs most of the developed world. Nigerian naturalization law also departs from every other country surveyed by requiring, in addition to residency, a formal assessment of “community acceptability,” an assimilation standard with no direct legal parallel elsewhere in this study. Nigeria has no state religion clause in its constitution, but its preamble invokes “under God” nonetheless, and its naturalization oath asks new citizens to swear loyalty to the Federal Republic and its constitution, closing with “so help me God.”
Sources: Japanese Nationality Act; Japanese Constitution, Arts.12-13, 20; South Korean Nationality Act; Indian Citizenship Act 1955; Indian Constitution, Preamble, Art.51A; Russian Federal Law 138-FZ; Russian Constitution, Arts.6, 59, 67.1; Nigerian Constitution, s.27.
What “The Legal Architecture of Us” All Adds Up To
Step back from the country-by-country detail and a handful of patterns come into focus, and they’re worth carrying around as a working mental model of how the developed world actually thinks about belonging.
Birthright citizenship, as an unconditional legal default, is functionally a Western Hemisphere institution at this point. Canada, Mexico, Chile, Colombia, and Costa Rica all still grant it without much qualification. Nearly everywhere else, in Europe and East Asia alike, the trend for the past several decades has run the other direction, toward citizenship as something inherited from parents rather than something conferred automatically by geography. Australia and New Zealand made that same turn within living memory, in 1986 and 2006 respectively, which tells you this isn’t an ancient civilizational difference so much as a policy choice that most of the world has made recently and in the same direction.
Naturalization residency requirements span an enormous range, from Nigeria’s fifteen years at the top down to functionally zero for Hungary’s ethnic-descent applicants or India’s fast-tracked religious minorities. And the requirements aren’t static. Portugal just made its own rules meaningfully stricter in 2026, reversing course after years of relative openness, while Italy added a new language floor the same year. Whatever momentum exists toward easier naturalization globally, it isn’t universal, and it isn’t one-directional.
If I had to pick the single sharpest dividing line in the entire survey, it’s the naturalization oath, because the variation there tells you more about a country’s self-conception than almost anything else in its citizenship code. Nine of the forty-two jurisdictions require no oath at all: Switzerland, Belgium, Luxembourg, Sweden, Finland, Poland, Türkiye, Japan, and Chile. Four still direct that oath to a living monarch rather than to a constitution or a nation in the abstract: the UK, Canada, New Zealand, and Spain. Four more treat the oath as constitutive, meaning citizenship legally does not exist until the words are spoken: Greece, South Korea, the Czech Republic, and Slovakia. And Russia’s oath stands alone for ideological density, binding new citizens not just to law but to culture, history, and tradition as named legal obligations.
Church and state turn out to have almost no correlation with a country’s wealth or its neighborhood. You’ll find an official state religion in Costa Rica, Iceland, Norway, Denmark, and Greece, none of which anyone would describe as a theocracy in ordinary conversation. You’ll find strict, deliberate separation in France, Mexico, Japan, South Korea, Slovenia, and Portugal. And you’ll find no separation clause at all in Israel, where religious descent functions as a legal gateway to automatic citizenship, alongside the Netherlands and Chile, where researchers simply could not locate an express separation clause in the constitutional text despite both countries functioning as thoroughly secular societies in practice.
Equal protection under the law, something most people assume is a baseline feature of any developed democracy’s constitution, isn’t universal even among wealthy, stable nations. Australia has no general constitutional equality clause. Israel’s Basic Laws contain no textual equal-protection guarantee whatsoever. Both countries rely on judicial interpretation to fill that gap rather than codified text, which works reasonably well in practice but represents a meaningfully thinner form of legal protection than an explicit constitutional guarantee provides.
And the right to petition your own government, the third leg of the speech-assembly-petition stool that Americans take for granted as a single package, turns out to be the piece most frequently missing. Ireland, Iceland, Sweden, Norway, Finland, Canada, Australia, New Zealand, India, Nigeria, and Israel all lack an express constitutional petition clause, even in cases where the same country protects speech and assembly robustly. Apparently it’s much easier for a constitutional drafter to guarantee that citizens can speak and gather than to guarantee they get a formal channel to actually be heard by their own government.
None of this is abstract trivia if you spend your career, as I do, thinking about how families and institutions organize belonging, obligation, and succession across generations. A country’s citizenship law is its own dynastic sufficiency question, answered at civilizational scale: what do you owe to be part of this, and what does the collective owe you in return. The answers vary more than most people assume, and the variation isn’t random. It tracks history, religion, colonial legacy, and, in a few cases like Portugal’s and Hungary’s, recent and deliberate political choices. Worth knowing, whether you’re planning a client’s estate or just trying to understand why the news out of one country’s immigration debate sounds nothing like the news out of another’s.
A note on sourcing: this piece condenses a much longer working matrix built from primary legal sources across all forty-two jurisdictions, including constitutions, nationality statutes, and official gazette entries, cited at the end of each section above. Where a country’s law genuinely had no textual answer to one of the seven questions, that gap is described as such rather than papered over with a guess. Treat the residency and language requirements described here as accurate to the August 2026 research date; several of these laws, particularly Portugal’s, Italy’s, and Finland’s, changed materially within the prior two years and may change again.
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