The president revealed that the attacks were conducted without warning, were intended not to stop but to kill all persons on the boats, and succeeded in their missions.

Trump has claimed that his victims are "narco-terrorists" who were planning to deliver illegal drugs to willing American buyers. He apparently believes that because these folks are presumably foreigners, they have no rights that he must honor and he may freely kill them. As far as we know, none of these nameless faceless persons was charged or convicted of any federal crime. We don't know if any were Americans. But we do know that all were just extrajudicially executed.

Can the president legally do this? In a word: NO. Here is the backstory.

The Constitution was ratified to establish federal powers and to limit them. Congress is established to write the laws and to declare war. The president is established to enforce the laws that Congress has written and to be commander-in-chief of the armed forces. Restraints are imposed on both. Congress may only enact legislation in the 16 discrete areas of governance articulated in the Constitution — and it may only legislate subject to all persons' natural rights identified and articulated in the Bill of Rights.

The president may only enforce the laws that Congress has written — he cannot craft his own. And he may employ the military only in defense of a real imminent military-style attack or to fight wars that Congress has declared. The Constitution prohibits the president from fighting undeclared wars, and federal law prohibits him from employing the military for law enforcement purposes.

The Fifth Amendment — in tandem with the 14th, which restrains the states — assures that no person's life, liberty or property may be taken without due process of law. Because the drafters of the amendment used the word "person" instead of "citizen," the courts have ruled consistently that this due process requirement is applicable to all human beings. Basically, wherever the government goes, it is subject to constitutional restraints.