Earlier quoted context omitted.
So you're arguing if the US declared war on Venezuela, that Venezuela could just use a drone to blow up the US president and that's just how war should work from now on? Because it's only a matter of years until drones get small and stealthy enough that nobody is safe; exploding pagers are a clear first step in this direction.
While I'm only adding to the choir of people telling you "of course," since I'm directly the person you're responding to it still feels worth saying: yes, of course, if America and Venezuela went to war, it's completely legal for Venezuela to attempt to kill the U.S. President. As an American, I certainly hope they would fail. But do I think it's legal? Yes: it's a targeted strike on the leader of an enemy country th…
So then China could, at any point, call up the US president and say "Look there's a drone in the room with you right now. Shut down all your nuclear facilities or I hereby declare war and you're dead within 10 seconds." Then failing that they could hit the VP next, Secretary of state, etc etc.
Point being the idea of sticking with WW2 "rules" with current and future technology is laughably implausible.
And I guarantee you the citizens of Israel would NOT think it's perfectly legit, legal, and fair if Netenyahu got assassinated with a drone along with his military commanders.