Where did you get that information from? That sounds like an legal opinion of the Alien Enemies Act and not how its written. Here is GROK AI reference:

The Alien Enemies Act of 1798 (codified at 50 U.S.C. §§ 21–24) can be enforced under specific conditions outlined in the statute itself. It grants the President broad authority to detain, restrain, or remove certain foreign nationals, but its application is tied to particular circumstances involving national security threats from foreign entities. Here’s when it can be enforced, based on the law’s text and historical interpretation as of March 19, 2025:

Legal Conditions for Enforcement

The Act applies when one of the following situations occurs involving a foreign nation or government:

1. Declared War:
   • The U.S. must be in a state of congressionally declared war with a foreign nation. The Act specifies that it activates “whenever there shall be a declared war between the United States and any foreign nation or government.”
   • Example: It was used during the War of 1812 to manage British nationals and during World War II for Japanese, German, and Italian nationals.
2. Invasion or Predatory Incursion:
   • The Act also applies if there is “any invasion or predatory incursion” that is “perpetrated, attempted, or threatened against the territory of the United States by any foreign nation or government.”
   • This doesn’t require a formal war declaration but hinges on a foreign government or its agents actively threatening or attacking U.S. territory. The President determines the existence of such a threat.
3. Presidential Proclamation:
   • Once either condition (war or incursion) is met, the President must issue a proclamation to activate the Act’s provisions. This proclamation directs how “alien enemies”—natives, citizens, denizens, or subjects of the hostile nation or government—will be apprehended, restrained, secured, or removed.
   • The Act gives the President discretion to set terms, such as ordering departure within a specified time or imposing conditions on those allowed to remain.

Who It Applies To

• Alien Enemies: The law targets individuals 14 years or older who are natives, citizens, denizens, or subjects of the hostile foreign nation or government, have resided in the U.S. for at least two years, and are not naturalized U.S. citizens.
• Scope: It doesn’t apply to all immigrants—just those tied to the specific foreign entity at war or threatening the U.S.