enemy alien: see alien.

alien, in law, any person residing in one political community while owing allegiance to another. A procedure known as naturalization permits aliens to become citizens.

Each nation establishes conditions upon which aliens will be admitted, and makes laws concerning them. Most countries, including the United States, forbid or limit the admission of criminals, paupers, and the diseased. Certain groups and nationalities may be unconditionally excluded from legal residence, but such discrimination is likely to cause international friction.

Aliens, while they reside in a country, are subject to its laws and not to those of their home country, except in cases of extraterritoriality jurisdiction. A state distinguishes between aliens who are merely traveling or living there temporarily and those who have come to stay or work; wider powers are assumed over the second group. In the United States, permanent resident status may entitle an alien to a "green card," and thus to seek employment, and aliens have many of the privileges afforded to citizens, including public assistance and the right to attend public schools, even if they are in the country illegally. The Immigration and Nationality (McCarran-Walter) Act of 1952 requires aliens to register each year with the Bureau of Citizenship and Immigration Services (formerly the Immigration and Naturalization Service).

As citizens of another country, aliens may call on it to intercede in legal matters. Their home state may point out or protest injustice and may also threaten reprisals; such situations have frequently caused international disputes. On the other hand, aliens may find asylum in a country to which they have fled, unless treaties of extradition provide for their return. A state may for political or legal reasons expel an alien who has been admitted, by a procedure called deportation.

In time of war, laws governing aliens are usually stricter, and enemy aliens (nationals of enemy countries) may be restricted in various ways. Treaties between most governments provide for reasonable periods at the beginning of hostilities during which aliens may withdraw under supervision. World War II saw registration requirements and the exclusion of enemy aliens from certain U.S. areas, but the removal from their homes and internment in camps of Japanese on the West Coast applied to Americans of Japanese descent as well as to aliens.

Population and economic pressures periodically cause host countries to become less hospitable to aliens. In the 20th cent., U.S. immigration and deportation laws have changed in reaction to varying conditions. The "Red Scare" at the end of World War I brought a wave of deportations of anarchists and other radicals. A 1986 federal immigration bill, aimed at reducing the number of illegal aliens, allowed many of those who had been in the country for some time to apply for amnesty and stay legally, and millions took advantage. In the 1990s politicians, including many in such states as California, where large numbers of illegal aliens reside, introduced state or federal legislation aimed at denying various privileges and benefits to aliens, in some cases even to those legally in the United States. A 1996 federal act led to a rapid increase in deportation of aliens who had not immigrated legally, and the INS grew to become the largest federal law-enforcement agency. Arizona voters passed (2004) a measure that requires public officials to turn in illegal immigrants who seek public services, including police and fire assistance.

Alien and Sedition Acts, 1798, four laws enacted by the Federalist-controlled U.S. Congress, allegedly in response to the hostile actions of the French Revolutionary government on the seas and in the councils of diplomacy (see XYZ Affair), but actually designed to destroy Thomas Jefferson's Republican party, which had openly expressed its sympathies for the French Revolutionaries. Depending on recent arrivals from Europe for much of their voting strength, the Republicans were adversely affected by the Naturalization Act, which postponed citizenship, and thus voting privileges, until the completion of 14 (rather than 5) years of residence, and by the Alien Act and the Alien Enemies Act, which gave the President the power to imprison or deport aliens suspected of activities posing a threat to the national government. President John Adams made no use of the alien acts. Most controversial, however, was the Sedition Act, devised to silence Republican criticism of the Federalists. Its broad proscription of spoken or written criticism of the government, the Congress, or the President virtually nullified the First Amendment freedoms of speech and the press. Prominent Jeffersonians, most of them journalists, such as John Daly Burk, James T. Callender, Thomas Cooper, William Duane (1760-1835), and Matthew Lyon were tried, and some were convicted, in sedition proceedings. The Alien and Sedition Acts provoked the Kentucky and Virginia Resolutions and did much to unify the Republican party and to foster Republican victory in the election of 1800. The Republican-controlled Congress repealed the Naturalization Act in 1802; the others were allowed to expire (1800-1801).

In law, one who resides in a country without becoming naturalized, retaining instead the citizenship of another country. The laws of most nations have long afforded aliens certain minimum standards of civilized treatment but have also restricted their employment and ownership of property. Under U.S. law, all aliens have had to register since 1940. Registration cards (“green cards”) enh1 them to obtain employment. Like citizens, aliens are protected by the U.S. Constitution, including the Bill of Rights and the due-process clause of the 14th Amendment. They remain subject to limitations under local laws, and residence in the U.S. is not a right but a privilege granted by Congress.

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Four laws passed by the U.S. Congress in 1798, in anticipation of war with France. The acts, precipitated by the XYZ Affair, restricted aliens and curtailed press criticism of the government. Aimed at French and Irish immigrants (who were mostly pro-France), they increased the waiting period for naturalization and authorized expulsion of aliens considered dangerous. The Alien and Sedition Acts were opposed by Thomas Jefferson and others and helped propel Jefferson to the presidency. They were repealed or had expired by 1802.

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