You are wrong. I did in NO WAY suggest that they have to wait till one fired.
I wrote "Self defence ceases to be possible once the aggression is over.
Here wasn't even an aggression." Aiming a weapon is already an aggression in such a context. They would not need to wait for a shot.


The definition of self defence is not up for debate, though. You cannot assert that something was done in self-defence if no aggression was ongoing.

You cannot shoot your neighbour next door just because you suspect he's got a weapon. You gotta wait till he threatens you with it.

You cannot shoot your neighbour next door just because he threatened you with his gun a while back and then returned to his apartment. The time for self defence has passed in this case.


The inflationary use of the excuse "self defense" by U.S. forces has gone too far. This was no self defence, raiding compounds is no self defence, bombing weddings is no self defence.
The term is defined (differently in different countries, with afaik no definition matching your interpretation) and has a very narrow application. You cannot occupy it as an excuse for offensive action. (This applies even to foreign policy, where the term has experienced inflationary use as well.)


To provide excuses and to argue in favour of the pilots who obviously killed innocents and committed war crimes (there's no way to argue around that in regard to the medevac van scene!) fosters an environment in which additional soldiers will feel justified to commit war crimes.