||The examples and perspective in this article deal primarily with the northern hemisphere and do not represent a worldwide view of the subject. (October 2010)|
|Legal status of persons|
In general, basic requirements for naturalization are that the applicant hold a legal status as a full-time resident for a minimum period of time and that the applicant promise to obey and uphold that country's laws, to which an oath or pledge of allegiance is sometimes added. Some countries also require that a naturalized national must renounce any other citizenship that they currently hold, forbidding dual citizenship, but whether this renunciation actually causes loss of the person's original citizenship will again depend on the laws of the countries involved.
Nationality is traditionally based either on jus soli ("right of the territory") or on jus sanguinis ("right of blood"), although it now usually mixes both. Whatever the case, 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 called stateless persons. In some rare cases, procedures of mass naturalization were passed. As naturalization laws were 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 the massive influx of stateless people which followed massive denationalizations and the expulsion of ethnic minorities from newly created nation states in the first part of the 20th century, but they also counted the (mostly aristocratic) Russians who had escaped the 1917 October Revolution and the war communism period, and then the Spanish refugees. 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 hadn't been naturalized, thus living in a judicial no man's land).
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 – jus matrimonii – or by having ancestors who are nationals of that country), in order to reduce the scope of this category. However, in some countries this system still maintains a large part of the immigrated population in an illegal status, albeit some massive regularizations (in Spain by José Luis Zapatero's government and in Italy by Berlusconi's government).
Different naturalization techniques by nation 
United Kingdom 
There has always been a distinction in the law of England and Wales between the subjects of the monarch and aliens: the monarch's subjects owed the monarch allegiance, and included those born in his or her dominions (natural-born subjects) and those who later gave him or her their allegiance (naturalised subjects). Today, the requirements for naturalisation as a citizen of the United Kingdom depend on whether or not one is the spouse or civil partner of a citizen. An applicant who is a spouse or civil partner of a British citizen 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
- 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 naturalisation. 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 spouses or civil partners of British citizens 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 language and knowledge of life in the UK standards apply as for those married to British citizens
All applicants for naturalisation must be of "good character". Naturalisation is at the discretion of the Home Secretary but is normally granted if the requirements are met.
United States 
Congress is given the power to prescribe a uniform rule of naturalization, which was administered by state courts. There was some confusion about which courts could naturalize; the final ruling was that it could be done by any "court of record having common-law jurisdiction and a clerk (prothonotary) and seal."
The Constitution also mentions "natural born citizen". The first naturalization Act (drafted by Thomas Jefferson) used the phrases "natural born" and "native born" interchangeably.
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 1795 set the initial parameters on naturalization: "free, White persons" who had been resident for five years or more. 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 Democratic-Republican Party 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 5-year veterans of the Navy or Marine Corps. Over 192,000 aliens were naturalized between May 9, 1918, and June 30, 1919, under an act of May 9, 1918. Laws enacted in 1919, 1926, 1940, and 1952 continued preferential treatment provisions for veterans.
Passage of the Fourteenth Amendment meant that, in theory, all persons born in the U.S., and subject to the jurisdiction thereof, are citizens regardless of race. Citizenship by birth in the United States, however, was not initially 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 enabling legislation for the naturalization aspects of the Fourteenth Amendment was the Naturalization Act of 1870, which allowed naturalization of "aliens of African nativity and to persons of African descent", but is silent about other races.
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.
The 1922 Cable Act specified that women marrying aliens ineligible for naturalization lose their US 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.
Following the Spanish American War in 1898, Philippine residents were classified as US 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 quotas did not apply to Filipinos who served in the United States Navy, which actively recruited in the Philippines at that time.
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 (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.
Illegal immigration became a major issue in the US at the end of the 20th century. The Immigration Reform and Control Act of 1986, while tightening border controls, also provided the opportunity of naturalization for illegal aliens who had been in the country for at least four years. Today, lawful permanent resident aliens can apply for naturalization in the U.S. after five years, unless they continue to be married to a U.S. citizen, in which case they can apply after three years of permanent residency.
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 or when legally adopted in the United States, depending on the visa under which the child was admitted to the U.S.
The Indian citizenship and nationality law and the Constitution of India provides single citizenship for the entire country. The provisions relating to citizenship at the commencement of the Constitution are contained in Articles 5 to 11 in Part II of the Constitution of India. Relevant Indian legislation is the Citizenship Act 1955, which has been amended by the Citizenship (Amendment) Act 1986, the Citizenship (Amendment) Act 1992, the Citizenship (Amendment) Act 2003, and the Citizenship (Amendment) Ordinance 2005. The Citizenship (Amendment) Act 2003 received the assent of the President of India on 7 January 2004 and came into force on 3 December 2004. The Citizenship (Amendment) Ordinance 2005 was promulgated by the President of India and came into force on 28 June 2005.
The People's Republic of China gives citizenship to persons with one or two parents with Chinese nationality who have not taken residence in other countries. The country also gives citizenship to persons born on its territory to stateless persons who have settled there. Furthermore, individuals may apply for nationality if they have a near relative with Chinese nationality, if they have settled in China, or if they present another legitimate reason.
The naturalization process starts with a written application. Applicants must submit three copies, written with a ball-point or fountain pen, to national authorities, and to provincial authorities in the Ministry of Public Security and the Public Security Bureau. Applicants must also submit original copies of a foreign passport, a residence permit, a permanent residence permit, and four two-and-a-half inch long pictures. According to the conditions outlined in the Nationality Law of the People's Republic of China, authorities may also require "any other material that the authority believes are related to the nationality application."
After Israel Declaration of Independence was made on 14 May 1948, the day before the British Mandate was due to expire as a result of the United Nations Partition Plan. The Israeli parliament created two laws regarding immigration, citizenship and naturalization: the Law of Return and the Israeli nationality law. The Law of Return, enacted on July 15, 1950, gives Jews living anywhere in the world the right to immigrate to Israel. This right to immigrate did not and still does not grant citizenship. In fact, for four years after Israel gained independence, there were no Israeli citizens.
On July 14, 1952, the Israeli parliament enacted the Israeli Nationality Law. The Nationality Law naturalized all citizens of Mandated Palestine, the inhabitants of Israel on July 15, 1952, and those who had legally resided in Israel between May 14, 1948 and July 14, 1952. The law further clarified that naturalization was available to immigrants who had arrived before Israel's creation, immigrants who arrived after statehood was granted, and those who did not come to Israel as immigrants but have since expressed desire to settle in Israel, with restriction. Naturalization applicants must also meet the following requirements: be over 18 years of age, have resided in Israel for three out of the five preceding years, have settled or intend to settle permanently in Israel, have some knowledge of Hebrew, and have renounced prior nationality or demonstrated ability to renounce nationality after becoming a citizen of Israel.
Because of Israel's relatively new and culturally-mixed identity, Israel does not grant citizenship to persons born on Israeli soil. Instead, the government chose to enact a jus sanguinis system, with the naturalization restrictions listed above. There is currently no legislation on second-generation immigrants (those born in Israel to immigrant parents). Furthermore, foreign spouses can apply for citizenship through the Minister of the Interior, but have a variety of restrictions and are not guaranteed citizenship.
South Africa 
Chapter 2 of the South African Citizenship Act, enacted on October 6, 1995, defines who is considered a naturalized citizen at the time of the act and also outlines the naturalization process for future immigrants.
Any person who immediately prior to the commencement of the act had been a South African citizen via naturalization, had been deemed to be a South African citizen by registration, or had been a citizen via naturalization of any of the former states now composing South Africa is now considered to be a naturalized citizen of South Africa.
Those wishing to apply for naturalization in the future must apply to the Minister of Home Affairs and must meet a slew of requirements. First, naturalization applicants must be over the age of 18 and must have been a permanent resident of South Africa for one year prior to application and for four out of the eight years prior to application. Applicants must also demonstrate good character and knowledge of the basic responsibilities and privileges of a South African citizen. The ability to communicate in one of the official languages of South Africa is also required. Applicants must show the intention to reside in South Africa after naturalization, and they are required to make a declaration of allegiance.
Being a naturalized South African citizen is a privilege, not a right. Even after meeting all the requirements and going through the naturalization process, the minister holds the right to deny citizenship. Foreign spouses of South African citizens can apply for naturalization after two years of marriage, but is subject to potential denial of the minister. The minister can also grant citizenship to minors, if their parent applies for them.
The minister also holds the power to revoke naturalization at any time for specific reasons listed in the Act. Reasons for revoking the naturalization certificate include marrying someone who is a citizen of another country and holding citizenship in another country, or applying for citizenship of another country without prior authorization for retention of citizenship. If a permanent resident is denied naturalization, he or she must wait at least one year before reapplying.
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.
- Argentina: 2 years continuous as a permanent resident immediately before the application (dual citizenship is allowed)
- Belgium: 3 years continuous (dual citizenship is allowed)
- Canada: 3 years (1,095 days in the country during five continuous years) as a permanent resident (dual citizenship is allowed)
- Chile: 5 years continuous (dual citizenship allowed).
- Colombia: 5 years as a permanent resident (dual citizenship is allowed).
- Denmark: 9 years continuous as a permanent resident immediately before the application (dual citizenship is not allowed)
- Finland 6 years of continuous residence (dual citizenship is allowed).
- France: 5 years continuous residency. Two years continuous residency for applicants who have had at least two years of higher education in France. (dual citizenship is allowed)
- Germany: 8 years continuous. (dual citizenship is allowed under specific circumstances only for some nationalities since June 2012)
- Ireland: 5 years over the last 9 years, including at least 1 year before applying. Dual citizenship is allowed, however Irish citizenship can be revoked if a naturalized citizen obtains citizenship of another state (other than automatic citizenship by marriage) subsequent to naturalization.
- Israel: 3 years out of the previous 5 as a permanent resident (dual citizenship is not allowed in the case of naturalisation, unless the applicant was exempt by the Minister of Interior). All naturalization requests are at the discretion of the Minister of the Interior.
- Italy: 10 years continuous. (dual citizenship is allowed)
- Japan: 5 years continuous. 3 years if married to a Japanese national. (dual citizenship not allowed)
- Netherlands: 5 years continuous (dual citizenship allowed under specific circumstances, such as acquiring a spouse's nationality, otherwise prohibited)
- New Zealand: 5 years continuous (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)
- Norway: 7 years out of the previous 10 (with out-of-realm vacations of up to 2 months per year) as a permanent resident immediately before the application (dual citizenship is permitted under certain conditions)
- Portugal: 6 years continuous (dual citizenship is allowed); in many cases, citizenship can be granted without any period of residence. Marriage generates citizenship only after 3 years.
- South Korea: 5 years continuous. 2 years if married to a South Korean national. (dual citizenship is only allowed for foreign born nationals who married to Korean citizen and overseas Koreans at least 65 years of age)
- Sweden: 5 years continuous (dual citizenship is allowed). 4 years continuous for stateless people and refugees.
- Switzerland: 12 years (the years between the age of 10 and 20 count double). (dual citizenship is allowed)
- Turkey: 5 years continuous residence (dual citizenship is allowed). The applicant must be a fluent speaker of the Turkish language.
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. In 1922, Greece massively naturalized all the Greek refugees coming back from Turkey. The second massive naturalization procedure was in favor of Armenian refugees coming from Turkey, who went to Syria, Lebanon or other former Ottoman countries. Reciprocally, Turkey massively naturalized the refugees of Turkish descent or other ethnic backgrounds in Muslim creed from aforementioned countries during redemption process.
After annexation of the territories east of the Curzon line by the Soviet Union in 1945, Soviets naturalized 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. Later on, Germany granted to ethnic German population in Russia and Kazakhstan full citizenship rights. Poland has a limited repatriation program in place.
The most recent massive naturalization case resulted from the Argentine economic crisis in the beginning of the 21st century. Existing or slightly updated 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 Argentine and Latin Americans acquired European nationality.
Since the Fourteenth Amendment to the United States Constitution grants citizenship only to those "born or naturalized in the United States, and subject to the jurisdiction thereof", and the original United States Constitution only grants Congress the power of naturalization, it could be argued that all acts of Congress that expand the right of citizenship are cases of massive naturalization. This includes the acts that extended U.S. citizenship to citizens of Puerto Rico, the United States Virgin Islands, Guam, and the Northern Mariana Islands, as well as the Indian Citizenship Act of 1924 which made all Native Americans citizens (most of them were previously excluded under the "jurisdiction" clause of the 14th Amendment).
Naturalizations in occupied territories 
The mass naturalization of native persons in occupied territories is illegal under the laws of war (Hague and Geneva Conventions). However, there have been many instances of such illegal mass naturalizations in the 20th century.
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. In another case, affecting only foreign-born citizens, denaturalization can refer to the loss of 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 US, the Bancroft Treaties in the 19th century regulated legislation concerning denaturalization.
After World War II 
Loss of U.S. citizenship was a consequence of foreign military service based on Section 349(a)(3) of the Immigration and Nationality Act until its provisions were found unconstitutional by the Supreme Court in 1967.
Yaser Esam Hamdi was a U.S. citizen captured in Afghanistan in 2001. He was fighting against U.S. and Afghan Northern Alliance forces, siding with the Taliban. He was named by the Bush administration as an illegal enemy combatant, and militarily detained in the country for almost three years without receiving any charges. On September 23, 2004, the United States Justice Department agreed to release Hamdi to Saudi Arabia on the condition that he give up his U.S. citizenship, though since it was done under duress it is possible that he can later reclaim it.
In the United Kingdom 
Section 4 of the British Nationality, Immigration and Asylum Act 2002 gave power to the Home Secretary to ‘deprive a person of a citizenship status if the Secretary of State is satisfied that the person has done anything seriously prejudicial to the vital interests’ of the United Kingdom etc., except in the case where such might render the person stateless.
Between World Wars 
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.
- "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.""
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 lose their naturalization.
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.
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.
During Vichy France, 15,000 persons, mostly Jews, were denaturalized (between June 1940 and August 1944), following the setting up, in July 1940, of a Commission charged of revision of naturalizations since the 1927 reform of the nationality law.
Before World War I 
In the United States, the proposed, but never ratified, Titles of Nobility amendment of 1810 would revoke the American citizenship of anyone who would "accept, claim, receive or retain, any title of nobility" or who would receive any gifts or honors from a foreign power.
See also 
- History of citizenship
- European Convention on Nationality
- Convention on the Reduction of Statelessness
- NATURALIZATION RECORDS IN THE USA, Schulze, Lorine McGinnis (2003). Retrieved April 23, 2005
- Citizenship Through Naturalization, ImmigrationAmerica.org
- Nationality Law of the People's Republic of China, GovHK.hk
- Guide and Instructions of Naturalization of Chinese Nationality, Hengyang, China website
- http://www.nytimes.com/learning/general/onthisday/big/0514.html Zionists Proclaim New State of Israel; Truman Recognizes it and Hopes for Peace] New York Times, 15 May 1948
- Warsoff, Louis A. "Citizenship in the State of Israel - a Comment." New York University Law Review 33(1958): 857-862. Web. 28 Nov. 2011
- Weil, Patrick. "Comparing Twenty-Five Nationality Laws." Citizenship Today: Global Perspectives and Practices. Washington, D.C.: Brookings Institution Press, 2001. 16-35. Print
- South African Citizenship Act. Pub. L. 1547. 6 Oct. 1995
- "South African Citizenship Through Naturalization." Immigration Assistant. N.p., 21 July 2009. Web. 1 Dec. 2011.
- Argentine Citizenship, JURIDICO VIRTUAL - BUENOS AIRES - REPUBLICA ARGENTINA
- Application for naturalization, Royaume de Bélgique – Affaires étrangères, Commerce extérieur et Coopération au Développement/Koninkrijk België – Buitenlandse Zaken
- Possess several nationalities, Royaume de Bélgique – Affaires étrangères, Commerce extérieur et Coopération au Développement/Koninkrijk België – Buitenlandse Zaken
- Becoming a Canadian citizen: Who can apply, Citizenship and Immigration Canada/Citoyenneté et Immigration Canadá
- Nationality – how to become a Danish national, New In Denmark
- , BGBl. I S. 1224
- Irish Citizenship – Becoming a Citizen of Ireland, MovetoIreland.com
- IND Verblijfwijzer
- Residence Requirements, The Department of Internal Affairs of New Zealand
- Citizenship by application, UDI - Norwedian Directorate of Immigration
- Lei Orgânica 2/2006, a statue from April 17, 2006.
- Nationality Law, Ministry of Government Legislation
- You must have been living in Sweden for a certain period, Migrationsverket
- Regular naturalisation, Swiss Confederation
- Turkish Nationality, Nüfus Müdürlüğü, My Merhaba.com
- CONSTITUIÇÃO DA REPÚBLICA DOS ESTADOS UNIDOS DO BRASIL (DE 24 DE FEVEREIRO DE 1891), Presidência da República - Casa Civil, art. 69
- Advice about Possible Loss of U.S. Citizenship and Foreign Military Service, Travel.State.Gov
- Part 1 Nationality, Office of Public Sector Information, at Web Cite.org
- For a comparative analysis of modes of loss of citizenship of 30 European states, see De Groot, G.R. and M. Vink (2010). Loss of Citizenship: Trends and Regulations in Europe. Comparative Report RSCAS/EUDO-CIT-Comp. 2010/4. Florence: EUDO Citizenship Observatory, pp. 52.
- John Hope Simpson, The Refugee Problem, Institute of International Affairs, October 1939, quoted by Hannah Arendt, The Origins of Totalitarianism (1951), section 2 on Imperialism, last chapter
- François Masure, "Etat et identité nationale. Un rapport ambigu à propos des naturalisés, in Journal des anthropologues, hors-série 2007, pp. 39–49 (see p. 48) (in french).