Instruct: Given a question, retrieve documents that can help answer the question.
Query: Can U.S. citizens maintain dual citizenship with another country?
If the parents of a child have different citizenships or are multiple citizens themselves, the child may gain multiple citizenship depending on whether and how jus soli and jus sanguinis apply for each citizenship. Some countries (e.g., Canada, the United States of America and many other countries in the Americas) regard all children born there automatically to be eligible to be citizens (jus soli) even if the parents are not legally present. For example, a child born in the United States to Norwegian parents automatically has dual citizenship with the United States and Norway, even though Norway usually restricts or forbids dual citizenship. There are exceptions, such as the child of a foreign diplomat living in the United States. Such a child would be eligible to become a lawful permanent resident, but not a citizen based on the U.S. birth.[29]This has led to birth tourism, so some countries have abolished jus soli or restricted it (i.e., at least one parent must be a citizen or a legal, permanent resident who has lived in the country for several years). Some countries forbid their citizens to renounce their citizenship or try to discourage them from doing so.[12] Policy changes may also render people to have multiple citizenship involuntarily, for example, when the sovereignty of a place is changed, the new country may declare the people on it to be citizens of the country.
Dual citizenship is strictly prohibited by the Singapore government. A dual citizen may have acquired citizenship by birth in a foreign country, by descent from a foreign citizen parent, or by registration. Singapore citizens who voluntarily and intentionally acquire citizenship of a foreign country after the age of 18 may be deprived of their Singapore citizenship by the Government. Foreigners who naturalise as Singaporean citizens are required to renounce all foreign citizenships. Persons who are born outside of Singapore and have at least one parent who is a Singapore citizen may register with a Singapore consulate within a year to acquire Singapore citizenship by descent. However, such persons who acquire foreign citizenship (by birth in a "jus soli" country or naturalisation in another country at an early age) must choose one citizenship before reaching 22 years of age.
Multiple citizens who travel to a country that claims them as a citizen may be required to enter or leave the country on that country's passport. For example, a United States Department of State web page on dual nationality contains the information that most US citizens, including dual nationals, must use a US passport to enter and leave the United States.[107] Under the terms of the South African Citizenship Act, it is an offence for someone aged at least 18 with South African citizenship and another citizenship to enter or depart the Republic of South Africa using the passport of another country. They may also be required, before leaving the country, to fulfill requirements ordinarily required of its resident citizens, including compulsory military service or exit permits.
Iceland allows dual citizenship. See also Icelandic nationality law. Liechtenstein allows citizens by descent to have dual citizenship, but foreigners wanting to naturalize must renounce their old citizenship. Norway allows dual citizenship only in exceptional cases. A Norwegian citizen who voluntarily acquires another citizenship automatically loses Norwegian citizenship without notification, and foreigners wanting to naturalize must usually renounce their old citizenship. For details, see Norwegian nationality law - Dual citizenship. Switzerland allows dual citizenship, but the conditions for the naturalization of foreigners vary from canton to canton. Male Swiss citizens under the age of 25, including male dual citizens, are required to perform military or civilian service (women can do it voluntarily), and Swiss citizens (men and women) are not allowed to work for a foreign (non-Swiss) military. Foreign military service is a felony for Swiss citizens (the Swiss Guards of Vatican City are regarded as a "house police", not an army). In the Canton of Schaffhausen, voting is compulsory. For more details, see Swiss nationality law and Schweizer Bürgerrecht (in German).
However, a South African citizen who by a formal and voluntary act acquires the citizenship of another country, automatically loses his or her South African citizenship unless they apply for, and receive permission to retain their South African citizenship before acquiring the citizenship of the new country. A naturalized citizen however cannot apply for such a retention under the law. There is not a specific requirement to do so if residing in South Africa or if the claim is inevitable such as a dual Zimbabwean-South Africa possessing the Right of Abode in the UK then registering as a British Citizen but it is advised by the Department of Home Affairs. If a South African Citizen wishes to restore a previously lost Citizenship (usually by birth or of their ancestors) due to acquiring Citizenship of another country, for instance citizenship of one of the territories that the Soviet Union controlled, then it is not a Voluntary or Formal Act when applying and retention of South African Citizenship is not necessary. A South African citizen cannot possess the Right of Abode in the United Kingdom as they were not Commonwealth Citizens in 1983 unless they are a Commonwealth Citizen of another country, however if due to registration, British Citizenship and the Right of Abode is given simultaneously.
However, the consensus against dual nationality began to erode due to changes in social mores and attitudes. By the late 20th century it was becoming gradually accepted again.[2] Many states were lifting restrictions on dual citizenship. For example, the British Nationality Act 1948 removed restrictions on dual citizenship in the United Kingdom, the 1967 Afroyim v. Rusk ruling by the U.S. Supreme Court prohibited the U.S. government from involuntarily stripping citizenship from Americans over dual citizenship, and the Canadian Citizenship Act, 1976, removed restrictions on dual citizenship in Canada. The number of states allowing multiple citizenship further increased after a treaty in Europe requiring signatories to limit dual citizenship lapsed in the 1990s, and countries with high emigration rates began permitting it to maintain links with their respective diasporas.[5]
Some foreign countries do not permit their citizens to hold other citizenships at all. Bars on dual citizenship take a variety of forms, but two common provisions in such countries' laws are that a foreigner seeking to become a citizen of the country generally must obtain release from any other citizenships according to the laws of those other countries (a provision seen for example in South Korea and Austria), and that a person who was born with dual citizenship must choose whether to retain the local citizenship or the foreign citizenship upon reaching the age of majority (e.g. in Japan). In the 1990s, many individuals relinquishing citizenship were naturalized citizens returning to their countries of birth; for example, the State Department indicated to the JCT that many of the 858 U.S. citizens who renounced in 1994 were former Korean Americans who returned to South Korea and resumed their citizenship there, which under South Korean nationality law required them to give up their U.S. citizenship. By the late 1990s, the number of relinquishments had fallen to about 400 per year. The State Department speculated that the 1997 Asian financial crisis resulted in "fewer people renounc[ing] their U.S. citizenship as a condition of employment in an Asian country".
In accordance with the Law on Romanian Citizenship of 1991, Romanian citizens currently have the right to hold dual citizenship. Romanian citizens who apply for dual citizenship are not required to establish their residency in Romania and, if accepted, are granted all the same rights as non-dual citizens. The Romanian policy on dual citizenship is irrelevant to other states policy. In order to successfully become a dual citizen of Romania, a person must also meet the requirements of dual citizenship in the other country. There have been cases in which applicants have successfully restored their Romanian citizenship and as a result, lost citizenship of another country. The Romanian state does not claim responsibility for the loss of citizenship to another state as a result of being granted dual citizenship by Romania.
Most countries in the Americas allow dual citizenship (some only for citizens by descent or with other countries, usually also in the region, with which they have agreements). Some countries (e.g., Brazil, Bolivia) do not allow their citizens to renounce their citizenship, so they keep it even when naturalizing in a country that forbids dual citizenship. Most countries in the region observe unconditional jus soli, i.e. a child born there is regarded as a citizen even if the parents are not. Some countries (the Dominican Republic, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Uruguay) allow renunciation of citizenship only if it was involuntarily acquired by birth to non-citizen parents. Canada and the United States allow dual citizenship and are worldwide the only two developed economies to grant unconditional birthright citizenship. The United States taxes its citizens and non-citizen lawful permanent residents worldwide, even if they have never lived in the country. In 2014, the U.S. Department of State increased the fee for processing requests for renunciation of citizenship from $450 to $2,350.[112][113] Dual citizenship is restricted or forbidden, for example, in Cuba, Haiti, and Suriname.
Cyprus has been divided into a southern (Greek) and northern (Turkish) region since the Turkish invasion of northern Cyprus on the 20th of July 1974. Northern Cyprus is not generally recognized by the international community as a sovereign state.[129] The United Nations considers the declaration of independence by Northern Cyprus as legally invalid.[130][131] The United Nations recognises Northern Cyprus as territory of the Republic of Cyprus under Turkish occupation.[130] Turkey permits Citizens of Northern Cyprus to live and work in Turkey under the same requirements as Turkish citizens, and provides a special type of passport for Northern Cyprus citizens. The Czech Republic has allowed multiple citizenship since January 1, 2014.[132] Denmark allows dual citizenship since September 1, 2015. Note that not all Danish citizens are EU citizens (see below). Estonia forbids dual citizenship, but citizens by descent cannot be deprived of their Estonian citizenship, so they de facto can have dual citizenship. Finland allows dual citizenship. France allows dual citizenship. Germany allows dual citizenship with other EU countries and Switzerland; dual citizenship with other countries is possible with special permission or if obtained at birth; children of non-EU/non-Swiss legal permanent residents can have dual citizenship if born and grown up in Germany (the parents born and grown up abroad must have resided in Germany for at least eight years and must have had the legal-permanent-resident status for at least three years, and usually cannot have dual citizenship themselves). Greece allows dual citizenship. Hungary allows dual citizenship; grants dual citizenship to people living in, and having ancestors in territories which were annexed from Hungary at the end of World War I, provided they can still speak Hungarian. Ireland allows and encourages dual citizenship, but a naturalized citizen can lose Irish citizenship again when naturalizing in another country; Ireland was the last European country to abolish unconditional birthright citizenship [in 2004] in order to stop "birth tourism" and to replace it by a modified form: at least one parent must be a citizen or a legal permanent resident. Italy allows dual citizenship. In Latvia ever since October 1, 2013, dual citizenship has been allowed for citizens of member countries of EU, NATO and EFTA [Iceland, Liechtenstein, Norway, Switzerland]; citizens of Australia, Brazil, New Zealand; citizens of the counties that have mutual recognition of dual citizenship with Latvia; people who were granted the dual citizenship by the Cabinet of Ministers of Latvia; people who have applied for dual citizenship before the previous Latvian Citizenship law [1995]; ethnic Latvians or Livonians who registered Latvian citizenship can keep previous citizenships with any country. In Lithuania, Article 12 of the Lithuanian Constitution states that only in "individual cases provided for by law" is dual citizenship permitted. [Constitution of the Republic of Lithuania, adopted on Oct. 25, 1992, in force from November 2, 1992]. Luxembourg allows dual citizenship. Malta allows dual citizenship. In the Netherlands, dual citizenship is allowed under certain conditions: e.g., foreign citizenship may be kept if obtained at birth or in the event of naturalization via marriage. Poland does not deal with the issue of dual citizenship, but possession of another citizenship is tolerated since there are no penalties for its possession alone. However, penalties do exist for exercising foreign citizenship, such as identifying oneself to Polish authorities using a foreign identification document. Dual citizens are usually not exempted from their duties as Polish citizens such as entering/leaving Poland using Polish passport or Polish ID card. Under some circumstances, ethnic Poles can apply for the "Polish Card" [Karta Polaka]. (see below) Portugal allows dual citizenship. Romania allows dual citizenship. In Slovakia, dual citizenship is permitted to Slovak citizens who acquire a second citizenship by birth or through marriage; and to foreign nationals who apply for Slovak citizenship and meet the requirements of the Citizenship Act. Please note that after the 'Hungarian-Slovak citizenship conflict' (year 2010) some restrictions to dual citizenship may apply.[133] Slovenia generally allows citizens by descent to have dual citizenship and forbids it only in certain cases, but foreigners wanting to naturalize must renounce their old citizenship. In Spain, Spanish citizens by descent can have dual citizenship; Spanish laws recognize a "dormant citizenship" for citizens naturalizing in Iberoamerican countries: They do not lose their citizenship, but their status and their rights as citizens of Spain—and of the EU—are inactive until they move back to Spain. Foreigners wanting to naturalize in Spain must usually renounce their old citizenship; exceptions are made for citizens of some Iberoamerican countries, Puerto Rico, Andorra, the Philippines, Equatorial Guinea, and Portugal. Since 2014, Spain has granted Spanish nationality to Sephardi Jews regardless of nationality.[134] Sweden allows dual citizenship. The United Kingdom allows dual citizenship. Note that not all British nationals are EU citizens (see below). On June 23, 2016, British citizens voted to leave the European Union. The effect on British Citizens' EU Citizenship is yet to be formally negotiated, so it is unclear yet what the result will be.
U.S. citizens are required by federal law to identify themselves with a U.S. passport, not with any other foreign passport, when entering or leaving the United States. The Supreme Court case of "Afroyim v. Rusk" declared that a U.S. citizen did not lose his citizenship by voting in an election in a foreign country, or by acquiring foreign citizenship, if they did not intend to lose U.S. citizenship. U.S. citizens who have dual citizenship do not lose their United States citizenship unless they renounce it officially.
Some countries have concluded treaties regulating travel and access to employment: A citizen of an EU country can live and work indefinitely in other EU countries and the four EFTA countries, and citizens of the EFTA countries can live and work in EU countries. Such EU citizens can vote in EU, but not national or local, elections. The Trans-Tasman Travel Arrangement between Australia and New Zealand allows their citizens to live and work in the other country. A citizen of a GCC member state (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates) can live and work in other member states, but dual citizenship (even with another GCC state) is not allowed. Indian citizens do not need a visa to travel to and work in Nepal or Bhutan (and vice versa), but none of the three countries allow dual citizenship.[49]
An Austrian citizen who acquires another citizenship by voluntary action automatically loses Austrian citizenship. The exception is in cases where permission to retain Austrian citizenship has been obtained in advance. This may be difficult to obtain, as the aim of the lawgiver is to reduce the number of dual citizenships granted. Exceptions are made for situations where it is in the interest of the Republic of Austria to grant this dual citizenship (e.g. when somebody is a celebrity in arts, sports, science, economy etc.), or in situations where the citizen would suffer hardship due to not having the second citizenship. If, for example, an Austrian citizen wants to obtain U.S. citizenship because he/she lives in the U.S. and, without a U.S. citizenship, would lose their green card due to being made to travel more than 180 days per year by their employer, then if they apply for permission to retain Austrian citizenship, that request is usually granted and has become almost a formality.
The United States, Canada, and Mexico all grant unconditional birthright citizenship and allow dual citizenship. The United States taxes its citizens and green card holders worldwide, even if they have never lived in the country. In Mexico, only naturalized citizens can lose their Mexican citizenship again (e.g., by naturalizing in another country). 
Nonetheless, another citizenship reform law was soon introduced after Helmut Kohl finished his last term as Chancellor. The Citizenship Law of 1999, which was officially taken into effect on 1 January 2000, has facilitated the acquisition of German citizenship for people born outside of Germany, making it available to Turkish immigrants after eight years of legal residence in the country. The law’s most innovative provision granted dual citizenship to Turkish-origin children born in Germany; however, by age twenty-three German-born Turks can no longer be dual citizens and must decide whether to keep their German citizenship or the citizenship of their parent’s country of birth.
As a result, the theory of perpetual allegiance largely fell out of favor with governments during the late 19th century. With the consensus of the time being that dual citizenship would only lead to diplomatic problems, more governments began prohibiting it, and revoking the nationality of citizens holding another nationality. By the mid-20th century, dual nationality was largely prohibited worldwide, although there were exceptions. For example, a series of U.S. Supreme Court rulings permitted Americans born with citizenship in another country to keep it without losing their U.S. citizenship.[2][4]
A person who is considered a citizen by more than one nation has "dual citizenship". It is possible for a United States citizen to have dual citizenship; this can be achieved in various ways, such as by birth in the United States to a parent who is a citizen of a foreign country (or in certain circumstances the foreign nationality may be transmitted even by a grandparent) by birth in another country to a parent(s) who is/are a United States citizen/s, or by having parents who are citizens of different countries. Anyone who becomes a naturalized U.S. citizen is required to renounce any prior "allegiance" to other countries during the naturalization ceremony; however, this renunciation of allegiance renunciation of citizenship to those countries.
Even countries which permit dual citizenship may bar dual citizens from government positions. Australia for example does not allow dual citizens to stand for election to Parliament, while Taiwan bars dual citizens from most public-sector positions. Diplomatic and consular positions present additional difficulties. The Vienna Convention on Diplomatic Relations and Vienna Convention on Consular Relations state that a country may refuse to receive a diplomat or consular officer who holds the citizenship of the receiving country. Based on this, the State Department does not receive U.S. citizens and non-citizen nationals as diplomats representing a foreign country to the United States. The State Department permits such individuals to represent a foreign country in its diplomatic mission at United Nations Headquarters in New York City, but while in such positions they enjoy only official acts immunity and not diplomatic immunity. Thus, an individual wishing to assume a diplomatic or consular position in the United States may choose to relinquish U.S. citizenship. One early example of this, which was described at the time as the first such case in U.S. diplomatic history, was Oskar R. Lange's decision to renounce citizenship in 1945 to become the Polish ambassador to the United States.
Some countries allow dual citizenship, but restrict the rights of dual citizens: in Egypt dual citizens cannot be elected to Parliament; in Armenia dual citizens cannot vote or be elected to Parliament; in Israel, members of Parliament must renounce any other citizenship before taking their seat in the Knesset; in Australia, dual citizens are ineligible to be elected to the Federal parliament.[30] In the 2017-18 Australian parliamentary eligibility crisis, fifteen members of Parliament were found to have been ineligible for election due to holding dual citizenship, although most had not been aware of the fact; in New Zealand, dual citizens may be elected to Parliament, but MPs once elected may not voluntarily become a citizen of another country, or take any act to have their foreign nationality recognised such as applying for a foreign passport. However, the only person to recently violate this, Harry Duynhoven, was protected by the passage of retroactive law; In the Philippines, dual citizens may not run for any local elective office.[31] In the independent states of the Commonwealth Caribbean, nationals of any Commonwealth country who meet local residency requirements are eligible to vote in elections and run for parliament, with one complicated caveat. Each of those countries has a provision barring anyone who "is by virtue of his own act, under any acknowledgment of allegiance, obedience or adherence to a foreign power or state" (to quote a representative provision from the constitution of St Vincent and the Grenadines[32]) from becoming a member of parliament. The precise meaning of those provisions is disputed, and is the subject of separate ongoing legal disputes in the countries.[33][34][35] Germany and Austria for the most part do not permit dual citizenship except for persons who obtain more than one citizenship at the time of birth.[36][37] Germans and Austrians can apply for special permission to keep their citizenship (Beibehaltungsgenehmigung) before taking a second one (for example, both Austria and the United States consider Arnold Schwarzenegger a citizen). In general, however, any Austrian who takes up a second citizenship will automatically lose Austrian citizenship. Since August 2007, Germany has recognised dual citizenship if the other citizenship is either one of an EU member country or a Swiss citizenship so that a permission is not required any more in these cases, and in some exceptional cases, non-EU and non-Swiss citizens can keep their old citizenship when they become citizens of Germany. For more details, see German nationality law Dual citizenship. Due to changes of the German law on dual citizenship, children of non-EU legal permanent residents can have dual citizenship if born and grown up in Germany (the foreign-born parents usually cannot have dual citizenship themselves). Acquisition of the nationality of Andorra, Portugal, the Philippines, Equatorial Guinea or Iberoamerican countries, is not sufficient to cause the loss of Spanish nationality by birth.[38] Spain has dual citizenship treaties with Bolivia, Chile, Colombia, Costa Rica, the Dominican Republic, Ecuador, Honduras, Guatemala, Nicaragua, Paraguay, Peru, Puerto Rico and Venezuela; Spaniards residing in these countries or territories do not lose their rights as Spaniards if they adopt that nationality.[39][40][41] For all other countries, Spanish citizenship is lost three years after the acquisition of the foreign citizenship unless the individual declares officially their will to retain Spanish citizenship (Spanish Nationality Law).[42] Upon request Spain has allowed persons from Puerto Rico to acquire Spanish citizenship.[43][44] On the other hand, foreign nationals who acquire Spanish nationality must relinquish their previous nationality, unless they are natural-born citizens of an Iberoamerican country, Andorra, the Philippines, Equatorial Guinea or Portugal even if these countries do not grant their citizens a similar treatment, or Sephardi Jews. See also the section on "dormant" citizenship. Prior to 2011, South Korea did not permit dual citizenship after the age of 21. Now a limited number of persons can have it.[45] For details, see South Korean nationality law#Dual citizenship. Like Germans and Austrians, citizens of South Africa must apply for permission to keep their citizenship when acquiring the citizenship of another country.[46] The Turkish government requires that Turkish citizens who apply for another nationality inform the appropriate Turkish officials (the nearest Turkish embassy or consulate abroad) and provide the original naturalization certificate, Turkish birth certificate, document showing completion of military service (for males), marriage certificate (if applicable) and four photographs. Dual nationals are not compelled to use a Turkish passport to enter and leave Turkey; it is permitted to travel with a valid foreign passport and the Turkish National ID card. Pakistan allows dual citizenship with only 19 countries: Australia, Belgium, Bahrain, Canada, Denmark, Egypt, Finland, France, Iceland, Ireland, Italy, Jordan, the Netherlands, New Zealand, Sweden, Switzerland, Syria, the United Kingdom, and the United States.[47]
Despite the fact that the Statuto Albertino did not make any reference to equality or inequality between the sexes, the precept of the wife's subordination to the husband - one having ancient antecedents - was prevalent in the basic legal system (the legislative meaning). There are numerous examples in the codified law, such as article 144 of the Civil Code of 1939 and, specifically, law number 555 of 13 June 1912 "On Italian Citizenship". Law 555 established the primacy of the husband in the marriage and the subordination of the wife and the children to his events pertinent to his citizenship. It established:Of central importance for the diaspora of Italians in many countries, as it relates to the holding of Italian citizenship alongside another citizenship, is article 7 of law number 555 of 1912. The provisions of this article gave immunity to some living Italian children from the citizenship events of their fathers. If the child was born to an Italian father in a "jus soli" country, the child was born with the Italian citizenship of the father and also with the citizenship of the country where he or she was born. That is to say that the child was born as a dual citizen. Children born with dual citizenship in this form were allowed to maintain their dual status in the event that the father naturalised later, thus parting with Italian citizenship. Moreover, Italy has not imposed limitations on the number of generations of its citizens who might be born outside Italy, even as holders of citizenship foreign to Italy.
Since 2008, Poland has granted the "Polish Card" (Karta Polaka) to ethnic Poles who are citizens of the successor states of the former Soviet Union and can prove they have Polish ancestors and knowledge of the Polish language and declare their Polish ethnicity in written form. Holders of the Card are not regarded as citizens, but enjoy some privileges other foreigners do not, e.g. entry visa, right to work, education, or healthcare in Poland. As stated above, Poland currently has no specific laws on dual citizenship; a second citizenship is tolerated, but not recognized. Turkey allows its citizens to have dual citizenship if they inform the authorities before acquiring the second citizenship (see above), and former Turkish citizens who have given up their Turkish citizenship (for example, because they have naturalized in a country that usually does not permit dual citizenship, such as Germany, Austria or the Netherlands) can apply for the "Blue Card" (Mavi Kart), which gives them some citizens' rights back, e.g. the right to live and work in Turkey, the right to possess land or the right to inherit, but not, for example, the right to vote. Overseas citizenship of India: The Constitution of India does not permit dual citizenship or dual nationality, except for minors where the second nationality was involuntarily acquired. Indian authorities interpreted this to mean a person cannot have another country's passport while simultaneously holding an Indian one, even for a child claimed by another country as its citizen, who may be required by the laws of this country to use the corresponding passports for foreign travel (such as a child born in the United States to Indian parents). Indian courts have given the executive branch wide discretion over this matter.
New Zealand has permitted dual or multiple citizenship since the creation of New Zealand citizenship on 1 January 1949, although dual citizens who actively acquired or exercised their other citizenship could lose their New Zealand citizenship if their continued citizenship was judged "not conducive to the public good". The modern wording is similar; dual citizens may lose New Zealand citizenship by acting "in a manner that is contrary to the interests of New Zealand". A New Zealand citizen who holds another citizenship may renounce their New Zealand citizenship (see below), although this may not be registered if they reside in New Zealand or the country is at war.
Based on the U.S. Department of State regulation on dual citizenship (7 FAM 082), the Supreme Court of the United States has stated that dual citizenship is a "status long recognized in the law" and that "a person may have and exercise rights of nationality in two countries and be subject to the responsibilities of both. The mere fact he asserts the rights of one citizenship does not, without more, mean that he renounces the other", "Kawakita v. U.S.", 343 U.S. 717 (1952). In "Schneider v. Rusk", 377 U.S. 163 (1964), the U.S. Supreme Court ruled that a naturalized U.S. citizen has the right to return to his native country and to resume his former citizenship, and also to remain a U.S. citizen even if he never returns to the United States.
The "dormant citizenship" exists for example in Spain: Spanish citizens who have naturalized in an Iberoamerican country and have kept their Spanish citizenship are dual citizens, but have lost many of the rights of Spanish citizens resident in Spain—and hence the EU—until they move back to Spain. Some countries offer former citizens or citizens of former colonies of the country a simplified (re-)naturalization process. Depending on the laws of the two countries in question, dual citizenship may or may not be allowed. For details, see "right of return".[50]
Some African countries restrict or forbid dual citizenship. It is allowed for example in Angola, Burundi, Comoros, Cabo Verde, Côte d'Ivoire, Djibouti, Gabon, Gambia, Ghana, Kenya, Mali, Morocco, Mozambique, Niger, Nigeria, Rwanda, Senegal, São Tomé and Príncipe, Sierra Leone, Sudan, Tunisia, Uganda and Zambia. Eritreans, Egyptians, and South Africans[26] wanting to take another citizenship need a permission to maintain their citizenship. Eritrea taxes its citizens worldwide, even if they have never lived in the country.[111] Lesotho restricts dual citizenship, but observes jus soli.