Alien Enemies Act: A Fraught and Rarely Used Law

In 1798, during a feared invasion by France, the U.S. government enacted a set of four bills targeting immigrants and noncitizens known as the Alien and Sedition Acts. Three of the four bills either expired or were repealed during President John Adams’ tenure. However, one of the original bills endured — the Alien Enemies Act. This law remains in effect today and allows the sitting president wartime authority to apprehend, intern, and deport immigrants who originate from an “enemy nation.” 

The Alien Enemies Act has been invoked three times in our nation’s history, each time during a major conflict: the War of 1812, World War I, and World War II. The most well-known use of the law occurred when President Franklin Roosevelt authorized anyone suspected of being an “enemy to the U.S.” to be held in camps or military facilities across the nation without trial. According to the National Archives, this affected about 31,000 immigrant aliens and their families of Japanese, German, and Italian descent.

This law was used to intern innocent people based solely on their country of origin and without due process. Some politicians and organizations argue that the law of war authority established in the 1700s does not align with U.S. human rights principles of today. It specifies that people who live in the U.S. during a time of war or invasion, who are natives of the enemy country, will be deemed as “alien enemies” and treated as prisoners of war without a trial. The Alien Enemies Act’s key provisions codified in title 50 U.S.C. chapter 3, section 21 state:

Whenever there is declared war between the United States and any foreign nation or government, or any invasion . . . is perpetrated, attempted, or threatened against the territory of the United States by any foreign nation or government, and the President makes public proclamation of the event, all natives, citizens, denizens, or subjects of the hostile nation or government, being of the age of fourteen years and upward, who shall be within the United States and not actually naturalized, shall be liable to be apprehended, restrained, secured, and removed as alien enemies.

Over the years, some lawmakers have declared the Alien Enemies Act is unjust and violates human and civil rights. In 1988, Congress apologized for the unlawful detainment of Japanese Americans and people with Italian ancestry, acknowledging that the law was invoked because of “racial prejudice” and “wartime hysteria.” Although apologies and reparations have been issued by Congress in the aftermath of its enforcement, the law still remains intact and has not changed much since 1798, despite attempts to reform the controversial law.

In his inauguration speech on January 20, 2025, President Trump declared that he would invoke the Alien Enemies Act to deal with the “invasion” at the southern border of the U.S. While his words aim to protect the U.S. from noncitizen criminals, there is question about the legitimacy of this statement, as no foreign nation is declaring, threatening, or invading the U.S.

Some politicians argue that unlawful migration is an invasion. For example, Texas claimed its constitutional right to “engage in war” in a 2024 lawsuit concerning immigration enforcement and border management; however, states relinquished rights of war to the federal government long ago, and Texas did not win this case. 

As commander in chief, President Trump has the authority to invoke the wartime act to inter or remove citizens and natives of a “hostile nation” from U.S. soil during war, but Congress must eventually approve or deny the country’s involvement in war. A president is able to invoke this act, and Congress might even approve it, but it is likely to meet legal challenges all the way up to the Supreme Court.

This article was written by Natasha Rogers and Sherilyn Stevenson, advocacy researchers and writers for Mormon Women for Ethical Government.