SO Killing Omar Kadar in battle is fine then?
That is what I meant
While I will avoid deep specifics, the Rules of Engagement are usually something to the effect of "minimum force required to engage and neutralize the threat". If the guy is unarmed, he is not considered a threat anymore. Putting a bullet in him will get you court-martialed:
http://www.macleans.ca/news/canada/capt-robert-semrau-dismissed-from-the-forces/
I can easily understand if soldiers eventually decide not to follow the rules.
You might. But Canadian society likely won't. And that's why commanders take a dim view of undisciplined actions that violate standing policies, laws and ROEs. The above case should prove instructive. We could argue that Capt. Semrau did the morally right thing putting that fighter out of his misery. However, the implications of allowing an individual to decide what should and should not be justifiable homicide in violation of the ROEs are huge. The military cannot allow soldiers to decide what lawful orders can be violated on personal judgment. And post-Somalia and post-Airborne Regiment, there's a strong sense that we would lose the support of Canadian society if we tolerated such behavior.
And I would argue it's what makes the military an admirable institution. The ultimate statement of professionalism is that you can have an enemy shooting at you one instant and then administer aid to save his life, without malice, the very next moment.
I will relate to you a second hand story. One of my bosses had the chance to serve with General Hillier when the General was a Colonel and my boss was a Captain in Bosnia. They got pinned down by sniper fire and were under strict ROEs that really limited return fire. The Captain's radio operator ran up to the two of them yelling, "Sir, they are shooting at us!" To which, then Col. Hillier calmly responded, "Son. Don't take it personally. They aren't shooting at you. They are shooting at the uniform you're wearing."
Our job is to exercise violence, on behalf of the state, in pursuit of our nation's objectives. Letting emotions get in the way, takes away the ability to analyse situations dispassionately, could cost us that nation's goodwill and support and ultimately make us far less capable. I'll take a disciplined soldier who isn't a great shot over a trigger happy marksmen any day.