These scenarios are so superficial it's not possible to make a just determination and I understand your retort is based on a response to someone you feel is not qualified to make an informed assessment of combat and the engagement of the enemy.
May I state, as an add on to your response, that we who now serve and have served our nation faithfully will/would never engage the enemy in a manner which ignores the Laws of War nor the standing RoE nor purposefully endangers, injures or kills innocent/non-combatants. To do so would be a violation of the GC/HC, International Law, the UCMJ and is punishable under the MCM's.
Does that mean we can/could at all times keep from endangering, injuring or killing the innocent. No! Does that mean there are some in the service of our Armed Forces who would violate the LoW and Roe? Absolutely. Just as there are cowards who serve and by their inactions cause the direct death of their comrades in arms. But for the most part our men and women who fight will not purposefully murder, maim or destroy the innocent. That is the purview of terrorists.
This is always unfortunate and it is a horrifying situation to be in.
There is a choice that every soldier must make when he or she is faced with the task of taking down a terrorist.
That choice is ... return fire or get killed. This is a choice that plagues good men and women in combat. I am sorry for those unlucky enough to get caught in the middle.
I would choose to live. I would fire on the terrorist in hopes of saving my life and the lives of everybody else concerned.
In terms of the USMC and the LOW, returning fire on those who attack us is an internationally accepted practice.
In combat, we often do not have the time or manpower to sweep a given area for civilians while engaging the enemy.
When civilians get injured as a result of a fire fight it is tragic. Though I think most people will run away when a gun fight breaks out. Those who refuse to do so are placing themselves in jeopardy.
These kinds of casulaties are not the result of a failure to obey the rules of engagement. There are an unfortunate side effect of a war.
Terrorist often choose to engage coalition forces when civilians are present because they like using civilians as shields.
The resulting fall out is often used by islam-o-nazi propagandists to further fan the flames of hate... despite the fact that the situation was created by the terrorists and those who order the attacks but lack the balls to carry them out.
I would like to say that I appreciate the kindness and respect you showed in addressing this issue. It means a lot to me that some people appreciate the sacrifice our armed forces make for us each and every day.