A judge swears in a new citizen. New York, 1910.

Naturalization is the acquisition of citizenship or nationality by an individual who was not a citizen or national of that country at birth. Generally, requirements for naturalization hold that the applicant maintains a full-time legal residency status for a minimum time period, be of good character, and promise, by means of swearing an oath in some cases, to abide by and uphold that nation’s laws.

Naturalization laws were originally created to accommodate limited numbers of immigrants needed for contributions toward nation building, as well as occasional cases of refugees seeking political asylum. During the first part of the twentieth century, however, western democracies were overwhelmed by large numbers of refugees, or expatriates, who, as victims of denaturalization, had been authoritatively stripped of their native citizenships and thus sought to be naturalized as citizens in other nations. Since that time, naturalization requirements in most western democracies, such as the United States, became stricter, due to national security concerns and economic capacity. Conversely, naturalization laws have become increasingly more relaxed in other areas, such as race requirements and marriage restrictions in the United States, for example.


Naturalization laws, in essence, aim toward granting qualified and determined individuals citizenship in nations that better reflect their personal, familial, political, and religious ideals than those in their native countries, and in particular to accommodate refugees, transcending racial, religious, or national barriers. At the same time, however, as contemporary nations struggle to maintain their right to self-determination there is a serious tension between the rights of the individual and the needs of the state that must be resolved in order for a global society of peace and justice to emerge.


The term naturalization originates in the concept of "natural born" citizens. In other words, the process of naturalization grants qualified personnel the same status, rights, and privileges as those who were "natively" or "naturally" born within a given nation's geographical parameters and subsequent territories.

Nationality is traditionally based either on jus soli ("right of the territory") or on jus sanguinis ("right of blood"), although nowadays it usually involves a combination of both. Naturalization can, in a theoretical sense, be considered the legal realization of a percieved moral human right to national membership and citizenship identity.[1]

In general, basic requirements for naturalization are that the applicant has held legal status as a full-time resident for a minimum period of time and that the applicant promises to obey and uphold that country's laws, to which an oath or pledge of allegiance may be required. Some countries also require that a naturalized national must renounce any other citizenship, forbidding dual citizenship, but whether this renunciation actually causes loss of the person's original citizenship depends on the laws of the countries involved.


Since the Roman Empire, ethical dilemmas surrounding the implications of granting citizenship, most prominently, political loyalty of immigrants seeking national membership, have caused a steady and increasingly complex evolution in immigration policies worldwide.[2] The massive increase in population flux due to globalization and the sharp increase in the numbers of refugees following World War I created an important class of non-citizens, permanent residents, similar to those previously classed as Civitas sine suffragio in the Roman Republic or denizens in Great Britain:

A denizen is a kind of middle state, between an alien and a natural-born subject, and partakes of both.[3]

Denaturalizations, or involuntary revocation of citizenship, were often used as a "weapon against political exiles" during World War I and thereafter.[4] As Hannah Arendt pointed out, internment camps became the "only nation" of such stateless people, since they were often considered "undesirable" and were stuck in an illegal situation (their country had expelled them or deprived them of their nationality, while they had not been naturalized, thus living in a judicial no man's land).[5]

As naturalization laws had been created to deal with the rare case of people separated from their nation state because they lived abroad (expatriates), Western democracies were not ready to naturalize this massive influx of stateless people—the two greatest such minorities after World War I were the Jews and the Armenians, but they also included the (mostly aristocratic) Russians who had escaped the 1917 October Revolution and the war communism period (1918 to 1921), and then the Spanish refugees.

After World War II, the increase in international migrations created a new category of refugees, most of them economic refugees. For economic, political, humanitarian, and pragmatic reasons, many states passed laws allowing a person to acquire their citizenship after birth (such as by marriage to a national or by having ancestors who were nationals of that country), in order to reduce the size of this category. In some rare cases, procedures of mass naturalization were passed.

Naturalization laws


French nationality law is historically based on the principle of jus soli, according to Ernest Renan's definition, as opposed to the German definition of nationality formalized by Fichte. However, elements of jus sanguinis have been included in the French code, especially during the 1992 reform, which forced children born in France of foreign parents to request French nationality at adulthood, instead of being automatically accorded it. As in most other countries, but differing from the U.S., children born in France to tourists or short term visitors do not acquire French citizenship by virtue of birth in France: residency must be proven. As immigration became more and more of a political theme in the 1980s, both left- and right-wing governments have issued several laws restricting more and more the possibilities of being naturalized.

Generally, a person may apply for French citizenship by naturalization after five years residence in France. Exceptions to the residence period include:

  • The residence period is reduced to two years for those who are graduates of a French university or grande école
  • The residence period may be waived for citizens of French speaking countries or for those who have served in the French military.

United Kingdom

There had always been a distinction in English law between the subjects of the monarch and aliens: The monarch's subjects owed him (or her) allegiance, and included those born in his dominions (natural-born subjects) and those who later gave him their allegiance (naturalized subjects).

The modern requirements for naturalization as a British citizen depend on whether one is married to a British citizen or not. All applicants for naturalization must be of "good character." Naturalization is at the discretion of the Home Secretary but is normally granted if the requirements are met.

For those married to a British citizen the applicant must:

  • Hold indefinite leave to remain in the UK (or an equivalent such as Right of Abode or Irish citizenship)
  • Have lived legally in the UK for three years
  • Be of "good character" as deemed by the Home Office (the Home Office will carry out checks with the police and other Government departments)
  • Been outside of the UK no more than 90 days during the one-year period prior to filing the application.
  • Show sufficient knowledge of life in the UK, either by passing the Life in the United Kingdom test or by attending combined English language and citizenship classes. Proof of this must be supplied with one's application for naturalization. Those aged 65 or over may be able to claim exemption.
  • Meet specified English, Welsh or Scottish Gaelic language competence standards. Those who pass the Life in the UK test are deemed to meet English language requirements.

For those not married to a British citizen the requirements are:

  • At least five years legal residence in the UK
  • Been outside of the UK no more than 90 days during the one-year period prior to filing the application.
  • Indefinite leave to remain or equivalent must have been held for 12 months
  • The applicant must intend to continue to live in the UK or work overseas for the UK government or a British corporation or association.
  • The same "good character" standards apply as for those married to British citizens
  • The same language and knowledge of life in the UK standards apply as for those married to British citizens

United States

United States naturalization certificate for Emanuel Theodore Bronner, June 10, 1936

In the United States of America, naturalization is mentioned in the Constitution. The Constitution also mentions "natural born citizen." The first naturalization Act (drafted by Thomas Jefferson) used the phrases "natural born" and "native born" interchangeably. To be "naturalized" therefore means to become as if "natural born"—a citizen.

There is an interesting loophole here in that the Constitution does not mandate race-neutral naturalization. Until 1952, the Naturalization Acts written by Congress still allowed only white persons to become naturalized as citizens (except for two years in the 1870s, which the Supreme Court declared to be a mistake).

Naturalization is also mentioned in the Fourteenth Amendment. Before that Amendment, individual states set their own standards for citizenship. The Amendment states that "all persons born or naturalized in the United States and subject to the jurisdiction thereof shall be citizens of the United States and of the State in which they reside."

The Naturalization Act of 1790 set the initial parameters on naturalization: Naturalization was limited to "free, white persons" and thus left out indentured servants, slaves, free African-Americans, and later Asian Americans. It also required immigrants to be of "good moral character," and to have been resident for two years or more. The Naturalization Act of 1795 increased the period of required residence to five years and made naturalization a two-step process by introducing the Declaration of Intent. The Naturalization Act of 1798, part of the Alien and Sedition Acts, was passed by the Federalists and extended the residency requirement from five to fourteen years. It specifically targeted Irish and French immigrants who were involved in anti-Federalist politics. It was repealed in 1802.

An 1862 law allowed honorably discharged Army veterans of any war to petition for naturalization, without having filed a declaration of intent, after only one year of residence in the United States. An 1894 law extended the same privilege to honorably discharged five-year veterans of the Navy or Marine Corps. Laws enacted in 1919, 1926, 1940, and 1952 continued preferential treatment provisions for veterans.[6]

Passage of the Fourteenth Amendment in 1868 meant that, in theory, all persons born in the U.S. are citizens regardless of race. The enabling legislation for the naturalization aspects of the Fourteenth Amendment was the 1875 Page Act, which allowed naturalization of "aliens of African nativity and to persons of African descent," but was silent about other races. Citizenship by birth in the United States was not granted to Asians until 1898, when the Supreme Court held that the Fourteenth Amendment did apply to Asians born in the United States in United States v. Wong Kim Ark.

The 1882 Chinese Exclusion Act banned Chinese workers and specifically barred them from naturalization. The Immigration Act of 1917, (Barred Zone Act) extended those restrictions to almost all Asians.

Following the Spanish American War in 1898, Philippine residents were classified as U.S. nationals. But the 1934 Tydings-McDuffie Act, or Philippine Independence Act, reclassified Filipinos as aliens, and set a quota of 50 immigrants per year, and otherwise applying the Immigration Act of 1924 to them.

The 1922 Cable Act specified that women marrying aliens ineligible for naturalization lose their U.S. citizenship. At the time, all Asians were ineligible for naturalization. The Immigration Act of 1924 barred entry of all those ineligible for naturalization, which again meant non-Filipino Asians.

Asians were first permitted naturalization by the 1943 Magnuson Act, which repealed the Chinese Exclusion Act. India and the Philippines were allowed 100 annual immigrants under the 1946 Filipino Naturalization Act. The War Brides Act of 1945 permitted soldiers to bring back their foreign wives and established precedent in naturalization through marriage.

The 1952 Immigration and Nationality Act (INA) (better known as the McCarran-Walter Act), lifted racial restrictions, but kept the quotas in place. The Immigration Act of 1965 finally allowed Asians and all persons from all nations be given equal access to immigration and naturalization. As a result of the September 11, 2001 attacks, the INA underwent a major restructuring beginning in March 2003 adding provisions regarding the admissibility and removability of terrorist suspects.

Illegal immigration became a major issue in the U.S. at the end of the twentieth century. The Immigration Reform and Control Act of 1986, while tightening border controls, also provided the opportunity for naturalization to illegal aliens who had been in the country for at least four years.

The Child Citizenship Act of 2000 streamlined the naturalization process for children adopted internationally. A child under age 18 who is adopted by at least one U.S. citizen parent, and is in the custody of the citizen parent(s), is now automatically naturalized once admitted to the United States as an immigrant.

Other countries

The following list is a short summary of the duration of legal residence before a national of a foreign state, without any cultural, historical, or marriage ties or connections to the state in question, can request citizenship under that state's naturalization laws.

  • Canada: Three years continuous residence (1,095 days) as a permanent resident (dual citizenship is allowed).[7]
  • Finland: Six years continuous residence or a total of 8 years since age 15; knowledge of at least one of Finnish, Swedish, or Finnish sign language.[8]
  • Netherlands: Five years continuous residence (dual citizenship allowed under specific circumstances, such as acquiring a spouse's nationality, otherwise prohibited).[9]
  • New Zealand: Five years continuous residence (reside in NZ for at least 240 days in each of those 5 years, 1,350 days in total) as a permanent resident immediately before the application (dual citizenship is allowed).[10]
  • Ireland: Five years residence over the last nine years, including at least one year continuous residence before applying. Dual citizenship is allowed.[11]

Massive naturalizations

A few rare massive naturalization procedures have been implemented by nation states. In 1891, Brazil granted naturalization to all aliens living in the country. A massive naturalization procedure was implemented in favor of Armenian refugees from Turkey, who went to Syria, Lebanon, or other former Ottoman countries, during the period of the Armenian genocide beginning in 1915. In 1922, Greece naturalized all the Greek refugees coming back from Turkey. Canada instituted a mass naturalization by Act of Parliament with the enactment of the Canadian Citizenship Act 1946.

In the beginning of the twenty-first century a massive naturalization case resulted from the Argentine economic crisis. Right of return laws in Spain and Italy allowed many of their diasporic descendants to obtain—in many cases to regain—naturalization in virtue of jus sanguinis, as in the Greek case. Hence, many Argentinians and Latin Americans acquired European nationality.


Denaturalization is the reverse of naturalization, when a state deprives one of its citizens of his or her citizenship. From the point of view of the individual, denaturalization means "revocation" or "loss" of citizenship. Denaturalization can be based on various legal justifications. The most severe form is the "stripping of citizenship" when denaturalization takes place as a penalty for actions considered criminal by the state, often only indirectly related to nationality, for instance for having served in a foreign military.

In countries that enforce single citizenship, voluntary naturalization in another country will lead to an automatic loss of the original citizenship; the language of the law often refers to such cases as "giving up one's citizenship" or (implicit) renunciation of citizenship. Unlike these two cases, which affect also native-born citizens, naturalized citizens can lose their citizenship by an annulment of naturalization, also known as "administrative denaturalization" where the original act of naturalization is found to be invalid, for instance due to an administrative error or if it had been based on fraud (including bribery). In the U.S., the Bancroft Treaties in the nineteenth century regulated legislation concerning denaturalization.

Before World War II

Before World War I, only a small number of countries had laws governing denaturalization that could be enforced against citizens guilty of "lacking patriotism." Such denaturalized citizens became stateless persons. During and after the war, most European countries passed amendments to revoke naturalization.[12]

It is important to note that starting with the period of World War I, many European states began to introduce laws which permitted their own citizens to be denaturalized and denationalized. The first was France, in 1915, with regard to naturalized citizens of "enemy" origins; in 1922 the example was followed by Belgium, which revoked the naturalization of citizens who had committed "anti-national" acts during the war; in 1926 the Fascist regime in Italy passed a similar law concerning citizens who had shown themselves to be "unworthy of Italian citizenship;" in 1933, it was Austria's turn, and so forth, until in 1935 the Nuremberg Laws divided German citizens into full citizens and citizens without political rights. These laws—and the mass statelessness that resulted—mark a decisive turning point in the life of the modern nation-state and its definitive emancipation from the naive notions of "people" and "citizen."[13]

The 1915 French denaturalization law applied only to naturalized citizens with "enemy origins" who had kept their original nationality. Later under Raymond Poincaré's government, another law was passed in 1927, which entitled the government to denaturalize any new citizen who committed acts contrary to the national interest.

In 1916, Portugal passed a law which automatically denaturalized all citizens born to a German father.

In 1922, Belgium enacted a law revoking the naturalization of persons accused of having committed "antinational acts" during the war; this was supplemented in 1934, by a new decree against people "in dereliction of their duties as Belgian citizens."

After 1926, in Italy, people who were deemed not to deserve the Italian citizenship or who were considered to represent a threat to the public order could be denaturalized.

Egypt in 1926 and Turkey in 1928, enacted laws authorizing denaturalization of any person threatening the public order. Austria passed a similar law in 1933, by which it could denaturalize any citizen who participated in a hostile action against the state. Russia also passed several similar decrees after 1921.[5]

In 1933, Nazi Germany passed a law authorizing it to denaturalize any person "living abroad" and began restricting the citizenship rights of naturalized citizens of Jewish origin, followed in 1935, by citizens by birth on the basis of the Nuremberg Laws.

After World War II

After annexation of the territories east of the Curzon line by the Soviet Union in 1945, Communist Poland denaturalized, en masse, all the inhabitants of those territories including ethnic Poles, as well as its other citizens who had been deported into the Soviet Union, mainly to Kazakhstan. Those persons were forcibly naturalized as Soviet citizens. In contrast to Germany, which afforded the ethnic German population in Russia and Kazakhstan full citizenship rights, Poland has only a very limited repatriation program and treated the repatriates as foreigners who needed to be naturalized.

Social issues

With the progression of history, naturalization has sparked a variety of social implications with its growing complexity. As individuals aspired toward obtaining citizenship in foreign nations, questions arose as to how many immigrants a given nation can admit in terms of socioeconomic status, character, criminal background, political values, and so forth.

The United States, for example, was once very welcoming to, and reliant upon, immigration for the purpose of nation building. The United States became widely known as a "nation of immigrants" or a global "melting pot," with naturalization as an open option for virtually anyone, regardless of race, gender, religion, national origin, and so forth, to fully and legally become a United States citizen. However, the United States tightened standards on naturalization requirements due in large part to an overwhelming influx of immigrants during the nineteenth and twentieth centuries. National security also led to stricter controls on naturalization, particularly since the terrorist attacks that took place on September 11th, 2001.

Stricter controls, along with lengthened waiting periods and higher processing costs for naturalization and/or permanent resident status, however, are often said to have contributed to the illegal immigration dilemma faced by the United States. Illegal immigrants, as a rule, are subject to detention and deportation if caught. Some politicians, however, have argued that amnesty should be awarded to gainfully employed illegal immigrants already residing in the United States along with tighter border controls. Opponents of amnesty have argued that illegal immigrants are law breakers who overwhelm the public welfare system and take jobs from American citizens; and that they should be returned to their home countries where they can take measures to immigrate legally if desired.

At the same time, however, political exile and refugees have become all too common conditions in the world. As contemporary nations struggle to maintain their right to self-determination, the human rights of these stateless people have led to a serious tension that must be resolved in order for a global society of peace and justice to emerge.


  1. Seyla Benhabib, The Rights of Others: Aliens, Residents, and Citizens (The Seeley Lectures) (Cambridge University Press, 2004, ISBN 0521538602).
  2. Louis Desipio and Rodolfo De La Garza, Making Americans, Remaking America: Immigration and Immigrant Policy (Dilemmas in American Politics) (Westview Press, 1998, ISBN 0813319447).
  3. William Blackstone, Article 1, Section 8, Clause 4 (Citizenship), Commentaries on the Laws of England: A Facsimile of the First Edition of 1765-1769 (Chicago, IL: University of Chicago Press, 1979). Retrieved April 24, 2018.
  4. Yossi Shain, Frontier of Loyalty: Political Exiles in the Age of the Nation-State (University of Michigan Press, 2005, ISBN 0472030426).
  5. 5.0 5.1 Hannah Arendt, The Origins of Totalitarianism (Harvest Books, 1973, ISBN 0156701537).
  6. Naturalization Records, Exceptions to the General Rule Retrieved April 24, 2018.
  7. Citizenship and Immigration Canada, Find out if you’re eligible — Citizenship Retrieved April 24, 2018.
  8. Finish Immigration Service, Finnish citizenship Retrieved April 24, 2018.
  9. IND, Naturalisation Retrieved April 24, 2018.
  10. New Zealand Government, Requirements for New Zealand Citizenship. Retrieved April 24, 2018.
  11. Irish Naturalisation and Immigration Service, Become an Irish citizen by naturalisation Retrieved April 24, 2018.
  12. John Hope Simpson, The Refugee Problem, Institute of International Affairs, October 1939, quoted by Hannah Arendt, The Origins of Totalitarianism (Harvest Books, 1973, ISBN 0156701537).
  13. Giorgio Agamben, Homo Sacer: Sovereign Power and Bare Life (Stanford University Press, 1998, ISBN 0804732183).


  • Agamben, Giorgio. Homo Sacer: Sovereign Power and Bare Life. Stanford University Press, 1998. ISBN 0804732183.
  • Arendt, Hannah. The Origins of Totalitarianism. Harvest Books, 1973. ISBN 0156701537.
  • Benhabib, Seyla. The Rights of Others: Aliens, Residents, and Citizens (The Seeley Lectures). Cambridge University Press, 2004. ISBN 0521538602.
  • Desipio, Louis and Rodolfo De La Garza. Making Americans, Remaking America: Immigration and Immigrant Policy (Dilemmas in American Politics). Westview Press, 1998. ISBN 0813319447.
  • Shain, Yossi. Frontier of Loyalty: Political Exiles in the Age of the Nation-State. University of Michigan Press, 2005. ISBN 0472030426.


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