Yes, there is “fog of war” and “collateral damage.” International law requires that combatants take steps to minimize that. And not intentionally target innocent life.
Even if you fail to avoid shooting innocent people and can find a scapegoat to save yourself from the consequences, homicide is definitely, unequivocally, illegal. And assassination (killing somebody that is helpless, like bombing its house or a sniper shooting a child) is even more illegal.
And any army that does not try at least to study a basic understanding of international war laws are a bunch of unprofessional criminals.
“an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, *which would be excessive in relation to the concrete and direct military advantage anticipated*”
Note that proportionality is ill-defined, leaving a lot of room for interpretation.
There is not a single country where I have the "right", granted by law, to shoot dead your 8Yo children. Period.
Some people, like dictators or criminals, just can jump over the law without consequences. And laws have exceptions that modify the punishment so in a few --extreme-- cases I could do it without serious consequences to me.
But: "Is an 'all you can kill' party and there are good chances that I will not be punished"; is still profoundly different as "is legal to kill children (as long as they are in a minority)".
> There is not a single country where I have the "right", granted by law, to shoot dead your 8Yo children. Period.
Sure there is.
If I'm a policeman, and in order to save lives I need to use my weapon and it results in the deaths of an 8 year old, that's permissible by law.
And so do the laws the of war.
If, in order to destroy the war fighting ability of an aggressor, I bomb a civilian center where the aggressor has placed offensive weapons, and is is judged by probability and proportionality to be reasonable, then it's legal.
It’s not.
Specific instances of killing innocent people where a number of factors are met is against international law.
Innocent people inevitably die in war. That’s why the world so desperately wants to avoid it.
But international law acknowledges that even if a actor does everything right, innocent people will die.