How Trump plans to use controversial war law from 1798 in order to send more immigrants to 'world's worst prison'

On Sunday (16 March), Donald Trump made the order to deport suspected members of a Venezuelan gang from the US to El Salvador.

A deal was struck with the country's President, Nayib Bukele, to place the immigrants in the nation's maximum security Terrorism Confinement Centre (CECOT).

It opened in 2023 and is one of the largest prisons in the world, which currently houses tens of thousands of people accused of having gang affiliations.

In a statement posted on Saturday, President Donald Trump claimed: "Tren de Aragua (TdA) is a designated Foreign Terrorist Organisation with thousands of members, many of whom have unlawfully infiltrated the United States and are conducting irregular warfare and undertaking hostile actions against the United States."

However, a federal judge ruled against the order, but as this decision was made while the plane with the suspected criminals was in international airspace, the Trump administration denied any wrongdoing.

The White House press secretary, Karoline Leavitt, said of the 238 alleged criminals being sent to the overseas prison: “A single judge in a single city cannot direct the movements of an aircraft carrier full of foreign alien terrorists who were physically expelled from US soil.”

She added that federal courts 'have no jurisdiction' over the president's foreign affairs.

But how was this all legal?

Trump had utilised an 18th century law, intended for use in wartime, as he claimed that the nation was facing an 'invasion' from a criminal organisation.

What is the Alien Enemies Act?

Known as the Alien Enemies Act of 1798, it is the wartime authority that gives the US President the power to detain or deport natives of an enemy nation.

It also allowed the leader to target the individuals, as long as they do not have an American citizenship, with no hearing required.

Originally put in place to combat foreign espionage during wars, the law can also be used against immigrants who haven't been proven guilty of anything.

As explained by Brennan Center: "It is an overbroad authority that may violate constitutional rights in wartime and is subject to abuse in peacetime."

The President deported alleged criminals who had not been confirmed to be convicted (El Salvador Presidency/Handout/Anadolu via Getty Images)

When was the Alien Enemies Act last used?

You'll have to go back to some of the darkest times in human history, with the act being invoked three times before: the War of 1812, World War I, and World War II.

In the latter two, the law was used as a means to target Austro-Hungarian, German, Italian, and Japanese immigrants based on their ancestry.

The act is known for forcibly relocating and incarcerating approximately 120,000 people of Japanese descent, some including US citizens, into internment camps.

What conditions can the president invoke the Alien Enemies Act in?

Normally, the president will invoke the Act during times of war, or when a foreign government threatens an 'invasion' or 'predatory' of US territory.

But as Congress is given the power to declare war, and not the president, he must wait to invoke the Alien Enemies Act based on a declared war.

"But the president need not wait for Congress to invoke the law based on a threatened or ongoing invasion or predatory incursion," Brennan Carter further explains.

This is why the American leader called the criminal group a 'foreign terrorist organisation' that is 'undertaking hostile actions', in justification of invoking the Act.

He wrote on Truth Social: "These are monsters sent into our Country by Crooked Joe Biden and the Radical Left Democrats. How dare they!"

The 78-year-old went on: "Thank you to El Salvador, and in particular President Bukele, for your understanding of this horrible situation, which was allowed to happen to the United States because of Democrat leadership.

"We will not forget."

Trump is adamant that he broke no laws and disobeyed no orders (Chip Somodevilla/Getty Images)

How seriously do the terms 'invasion' and 'predatory incursion' have to be taken?

While it is a wartime authority that was used primarily to hold Prisoners of War, the use of the Act outside of war seems a bit trickier.

According to the Constitution, 'invasion' is used literally, meaning large-scale attacks.

Other texts in the late 1700s also state that 'predatory incursion' is used to refer to smaller attacks.

This can be taken non-literally by anti-immigration groups and leaders, as the Act can technically be invoked to hit back at illegal immigration and narcotics trafficking, acting as a deportation authority, as Trump has found.

However, while it is considered abuse of power, it is unclear if this is not allowed.

Is it common to invoke the Alien Enemies Act outside of war?

Presidents Woodrow Wilson and Harry S. Truman used the the laws after the World Wars on immigrants and the internment of them, deporting a large number up until 1920 following World War I, and until 1951 after World War II.

But according to Ludecke v. Watkins in 1948, a narrow majority of the Supreme Court found that the Truman administration's excessive use of the Alien Enemies Act was not the judiciary's place to speak on the President as it was a 'political' matter, deciding when a war ends and how long wartime authorities go on for.