It's more like: as soon as you decide to fight, you willingly seek situations in which you might get killed by those who fight back. It's your choice. As a civilian, you try to avoid those situations.
So yes, there is a difference, and it has nothing to do with religion, but with choice.
This attitude--differentiating based on civilian-ness--is useful. Spreading it allows wars to do less damage, because if fewer civilians die then repairing the economy is easier afterwards. This leads to a host of good consequences, most importantly that it reduces the chance of renewed war later on.
Soldiers' lives aren't as important, in that sense. Sorry, but they're not. And soldiers are going to die no matter what; the cultural innovation here isn't treating soldiers' lives as worth little, it's treating civilians as highly valuable. Some of which has later spread to the soldiers as well...
I disagree. War must be deadly and costly for both sides. Human intercation is heavily based on deterrents. One can see that in interactions in small and big groups. Taking away the deadliness and cost of war will make it happen more often.
Besides the obvious example, there is peace in europe for so long only because the war before has been so costly and deadly.
A power in the world that can wage military conflicts without significant loss in their rows is a disaster for the world.
That's a bold statement and not supported by any evidence. Look at the Yugoslav wars. One of the most brutalized regions in WWII, and nobody gave a shit when it was about starting a new war some decades later.
Of course it is. If you choose to fight in a war, you forfeit your life. That's how wars work. You only win a battle by decimating your enemy. How is this bigotry?
Also, you believe your cause to be righteous, and so does your enemy. You both believe your cause to be so righteous, and your enemy to be so menacing to your cause, that you both have decided to go to arms over it.
On the other hand a civilian is a civilian. He didn't choose war, so he doesn't deserve to have his life taken away by a conflict he has no interest in.
You are wrong. You may decide to fight but not want to be killed nor kill anybody, but just want the war to stop. Most battles ended without decimating any side, and they can even end without much confrontation at all.