The Alien Enemies Act of 1798 is a U.S. federal law, formally titled part of “An Act Concerning Aliens,” codified under 50 U.S.C. §§ 21–24. It grants the President broad authority during a declared war
or when there’s an invasion or predatory incursion by a foreign nation or government to apprehend, restrain, secure, and remove “alien enemies” — individuals who are natives, citizens, or subjects of the hostile nation or government involved, and who are 14 years or older and not naturalized U.S. citizens. The law applies only in specific wartime or emergency contexts and requires the President to issue a public proclamation defining the scope of enforcement.
Historically, it’s one of four laws passed as the Alien and Sedition Acts during a tense period of potential conflict with France. Unlike its companion laws, which expired or were repealed, the Alien Enemies Act remains in effect today. It was notably used during World War I to intern German Americans and during World War II to detain and deport thousands of Japanese, German, and Italian nationals, alongside the more infamous internment of Japanese Americans (the latter often conflated with Executive Order 9066, which targeted citizens and relied on broader executive power).
In the recent March 2025 deportations to El Salvador, the Trump administration invoked this act to remove 137 alleged gang members, primarily from Venezuela’s Tren de Aragua, arguing their presence constituted a national security threat akin to a predatory incursion. Critics, including legal scholars and civil rights groups, contend this stretches the law beyond its intended scope, as no formal war or invasion by Venezuela exists. The act allows the President to set regulations for identifying and handling alien enemies—here, targeting suspected gang affiliates—but a federal judge’s March 15, 2025, order questioned its application, highlighting due process concerns. The White House defended its use, citing wartime-like authority over border security, though the legal battle continues as of March 18, 2025.
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