RE: You are confusing military ops with law enforcement ops. There is no “due process” requirement for military ops: it’s not a judicial procedure.
There is still the United Nations Convention on the Law of the Sea (UNCLOS)
Although the U.S. is not a formal party to UNCLOS, it has long stated that it considers most of its provisions as customary international law.
UNCLOS prohibits the use of force against foreign-flagged vessels on the high seas unless:
The vessel is stateless.
There is clear evidence of piracy, slave trading, or unauthorized broadcasting.
The vessel poses an imminent threat and self-defense is justified under Article 51 of the UN Charter.
We have also agreed to abide by International Human Rights and Humanitarian Law. Destruction of vessels and killing of occupants without judicial process may violate human rights norms, especially if the individuals are not combatants.
Extrajudicial killings are prohibited under international human rights law unless justified by immediate threat or armed conflict — neither of which typically applies to suspected drug boats.
Labeling drug cartels as terrorist organizations does not automatically justify military force under international law. Even terrorism conventions emphasize judicial cooperation over unilateral destruction.
You don’t execute a boat’s occupants simply out of suspicion, especially when they are not attacking you. The military can still exercise restraint and use all tools necessary at its disposal— including intercepting the boat, capturing the occupants as POWS and giving them a military trial.
Blowing them up should be a last resort. Think of the horror of making a possible mistake and killing innocent people instead.
It's the same with the ICC at the Hague: the US has wisely refused to sign onto that treaty as well and in fact, the Congress has authorized the use of force against the ICC should it try to grab or succeed in grabbing any US official or past or present member of the US armed forces.
A big part of Trump's electoral appeal was to reject the steady entanglement of US power by vague, leftist, international "human rights norms" that have almost always been used to protect enemies of the United States.
As far killing the innocent goes, just about any law enforcement exercise also carries with it the prospect of killing the innocent. The point here, as with any military operation, is to apply force until the opponent stops doing what you are trying to stop or gives in to your demands. In this case, that would be Maduro stopping the cartels and probably also ceasing military cooperation with China and Russia.
“The military can still exercise restraint and use all tools necessary at its disposal— including intercepting the boat, capturing the occupants as POWS and giving them a military trial.”
How about tracking the boats to their destination, confirming the delivery and cargo that was delivered, holding an immediate mass trial and killing all of them? Are we to object to dead drug traffickers?