None of the killings of Iraqi citizens by US soldiers in Iraq is self-defensive.
The US troops are the attackers here, not the defenders. The US project for Iraq is a conquest of someone else's country and a terrorizing of the citizens in their own home, with killing of all citizens who don't submit. That is the US project. No aspect of such a project can be self-defensive. If US troops were in their own country when they were attacked, or if US troops went to someone else's country to fight back against an attack, that might be defensive. But if you attack someone else in their own home, someone who was not attacking anyone, and they shoot back at you, and you then shoot at them, that's not self-defense on your part.
