Generally killing a member of the armed forces of an enemy nation during a war is not considered or described murder. It's a relevant and important distinction - and it's why Trump and his lickspittles designate the (alleged!) drug-runners as narco-terrorists with whom they can claim to be at war. This itself is an extension of the "war on terror" that extended the definition of combatant from the uniformed service-members of a nation state or at least a defined group in a conflict.
But to be clear, the "narco-terrorist" bullshit is a lot worse than the war-on-terror bullshit, because terrorists are at least explicitly trying to carry out violent acts with a political purpose (which is quite like war!) whereas (alleged! unevidenced!) drug runners are just... running drugs.