President Donald Trump secretly signed a groundbreaking directive authorizing military action against Latin American criminal groups his administration designated as foreign terrorist organizations, according to media reports on Friday.

The US Justice Department and Drug Enforcement Agency traditionally have taken the lead the in US action against drug cartels and other Latin American bad actors.

It is not clear what kind or level of military action Trump has in mind, or if he is serious about following through.

But any such action would be a game-changer, with enormous legal and diplomatic implications that the Trump administration would have to contend with.

To say the least, it is open to question whether drug cartels, which are decentralized and prone to splintering, might be degraded by US military action.

The chief concern is Mexico.

The Trump administration has designated six major Mexican cartels, including the Sinaloa Cartel and the Jalisco New Generation Cartel (Spanish abbr: CJNG), as terrorist organizations.

Even a limited surgical strike by US commandos or drones that did not injure civilians would ignite an intense nationalist backlash, upending US-Mexican relations.

President Claudia Sheinbaum on Friday “absolutely ruled out” US military engagement on Mexican soil, which she said would be tantamount to an “invasion.”  She stressed that close cooperation with the DEA and other US civilian agencies would continue.

Sovereignty concerns are deeply rooted in Mexican culture and the prospect of foreign forces conducting combat operations widely is considered a red line by Mexicans.

An explosion of anti-American sentiment and an accompanying collapse in extensive US-Mexican government-to-government collaboration would impact the operating environment of multinationals in Mexico.  Anti-American intimidation and violence could not be ruled out.

Companies active in Mexico should monitor the Trump administration’s actions closely.

Venezuelan and Haitian criminal groups also have been designated as terrorist organizations by the Trump administration.

The Trump administration on Thursday doubled to $50 million its reward for information leading to the arrest of authoritarian President Nicolas Maduro, alleging that he is a top global narco-trafficker who works with major criminal networks to ship fentanyl-laced cocaine into the US.

Venezuela’s diplomatic isolation and economic collapse would reduce the costs of any US military action, but the Trump administration could end up fighting the Venezuelan military.

Haiti is in a state of anarchy, with vicious criminal groups controlling much of the country and the humanitarian situation dire.  It is unclear what any US military action against a criminal group might achieve.