As April 20 nears, will Trump invoke Insurrection Act and militarise border?

Trump may invoke Insurrection Act, deploy military at border.

President Donald Trump signed an executive order declaring a national emergency at the southern border of the United States on 20 January 2025. The order includes a clause allowing for the possible use of the Insurrection Act of 1807, with a deadline of 90 days—20 April—for a decision on whether to invoke it.

The clause states that by this date, the Secretary of Defence and the Secretary of Homeland Security must submit a joint report to the President assessing border conditions and recommending whether further action, including the Insurrection Act, is necessary to achieve "complete operational control".

What the Insurrection Act permits

The Insurrection Act of 1807 gives the US President the authority to deploy the military and National Guard within the country to enforce the law in cases of unrest or resistance. It allows for the suppression of rebellion or domestic violence, even against US citizens.

It overrides the Posse Comitatus Act, a long-standing law that normally prevents the military from intervening in civilian law enforcement. The President alone decides when, where, and how to use these powers.

Not quite martial law

While often confused with martial law, the Insurrection Act is different. Martial law typically involves the military taking over the functions of civilian government, placing a general in control. By contrast, the Insurrection Act allows the military to support civilian authorities, but not replace them. Power remains with the President, not the armed forces.

Warnings over legal ambiguity

Legal scholars have long warned that the Insurrection Act is outdated and vague, with no clear definitions for terms like “insurrection” or “rebellion”. The Brennan Center for Justice argues the law is ripe for misuse and in urgent need of reform. They caution that a President could wield it inappropriately to stifle dissent or target political opponents.

Rising speculation ahead of April 20

With just days to go before the deadline, speculation is growing that Trump will indeed invoke the Act. Troops have already been sent to the border, and plans have been announced to house up to 30,000 migrants at Guantanamo Bay. However, the final report from defence and homeland security officials has not yet been released, heightening public concern about what might unfold.