Multiple citizenship

Many states did not recognize the right of their citizens to renounce their citizenship without permission because of policies that originated with the feudal theory of perpetual allegiance to the sovereign.

In addition, many 19th century European immigrants to the United States eventually returned to their homelands after naturalizing as US citizens and some cases then attempted to use their US citizenship for diplomatic protection.

The US State Department had to decide which US citizens it should protect and which were subjected to local law, resulting in tensions with immigrant communities in the US and European governments.

In 1874, President Ulysses S. Grant, in his annual message to Congress, decried the phenomenon of people "claiming the benefit of citizenship, while living in a foreign country, contributing in no manner to the performance of the duties of a citizen of the United States, and without intention at any time to return and undertake those duties, to use the claims to citizenship of the United States simply as a shield from the performance of the obligations of a citizen elsewhere."

The US State Department, invoking provisions of the Bancroft treaties, systematically stripped US citizenship from naturalized US citizens who returned to live in their native countries for extended periods of time.

Many individuals continued to hold dual nationality by circumstance of birth, including most children born in the US to non-citizen parents.

Although fully eliminating dual nationality proved to be legally impossible during this time, it was subjected to fierce condemnation and social shaming.

He had planned to travel to France on business but had been warned that he might be conscripted to fight in World War I, and when he contacted the State Department for assurances that "my constitutional privileges as an American citizen follow me wherever I go", he was informed that France would regard him as a citizen under its jus sanguinis laws, and that the State Department could give no assurances regarding his liability for military service if he voluntarily placed himself in French jurisdiction.

Countries that have taken active steps towards permitting multiple citizenship in recent years include Switzerland (since January 1, 1992) and Australia (since April 4, 2002).

In addition, a dual legal status can have positive effects on diasporic identification and commitment to causes in the homeland, as well as to a higher naturalization rate of immigrants in their countries of residence.

[89] The rise in tension between mainstream and migrant communities is cited as evidence of the need to maintain a strong national identity and culture.

They assert that the fact that a second citizenship can be obtained without giving anything up (such as the loss of public benefits, welfare, healthcare, retirement funds, and job opportunities in the country of origin in exchange for citizenship in a new country) both trivializes what it means to be a citizen[90] and nullifies the consequential, transformational, and psychological change that occurs in an individual when they go through the naturalization process.

[92] Proponents argue that dual citizenship can actually encourage political activity providing an avenue for immigrants who are unwilling to forsake their country of origin either out of loyalty or based on a feeling of separation from the mainstream society because of language, culture, religion, or ethnicity.

The reason for this is twofold: The degree of angst over the effects of dual citizenship seemingly corresponds to a country's model for managing immigration and ethnic diversity: People with multiple citizenship may be viewed as having dual loyalty, having the potential to act contrary to a government's interests, and this may lead to difficulties in acquiring government employment where security clearance may be required.

Contrary to common misconceptions, dual citizenship in itself is not the major problem in obtaining or retaining security clearance in the United States.

[101] This guideline has been followed in administrative rulings[102] by the United States Department of Defense (DoD) Defense Office of Hearings and Appeals[103] (DOHA) office of Industrial Security Clearance Review[104] (ISCR), which decides cases involving security clearances for Contractor personnel doing classified work for all DoD components.

[106] On the other hand, Israel may view some dual citizens as desirable candidates for its security services because of their ability to legitimately enter neighbouring states which are closed to Israeli passport holders.

David McAllister, who holds British and German citizenship, was minister president of the State of Lower-Saxony from July 1, 2010, to February 19, 2013.

A small controversy arose in 2005 when Michaëlle Jean was appointed the Governor General of Canada (official representative of the Queen).

A court case (see Sue v Hill) determined that the UK is a foreign power for purposes of this section of the constitution, despite Australia holding a common nationality with it at the time that the Constitution was written, and that Senator-elect Heather Hill had not been duly elected to the national parliament because at the time of her election she was a subject or citizen of a foreign power.

Adamkus was a high-ranking official in the Environmental Protection Agency, a federal government department, during his time in the United States.

It has been reported that some US citizens have relinquished US citizenship in order to avoid possible taxes, the expense and complexity of compliance, or because they have been deemed unacceptable to financial institutions in the wake of FATCA.

This can mean (in Iran,[133] Mexico,[134] many Arab countries, and former Soviet republics) that consular officials abroad may not have access to their citizens if they also hold local citizenship.

An example of this occurs in Israel, which permits multiple citizenships whilst also requiring compulsory military service for its citizens.

Several countries have entered into a Protocol relating to Military Obligations in Certain Cases of Double Nationality established at The Hague, 12 April 1930.

[138] The right to healthcare in countries with a public health service is often discussed in relation to immigration but is a non-issue as far as nationality is concerned.

Customary international law and precedent have since recognized the idea of dominant and effective nationality, with the Nottebohm case providing an important shift.

Dual citizenship is allowed in Angola, Burundi, Comoros, Cabo Verde, Côte d'Ivoire, Djibouti, Gabon, Gambia, Ghana, Kenya, Malawi, Mali, Morocco, Mozambique, Niger, Nigeria, Rwanda, Senegal, São Tomé and Príncipe, Sierra Leone, Sudan, Tunisia, Uganda, Zambia and Zimbabwe; others restrict or forbid dual citizenship.

Some countries, such as the Dominican Republic, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, and Uruguay, allow renunciation of citizenship only if it was involuntarily acquired by birth to non-citizen parents.

However, countries can limit the right to vote and work in certain sensitive fields (such as government, police, military) to local citizens only.