Soldiers life threatened by his own side.

[Tempus]

What I wished to explain was that, irrespective of their other deeds, the act of killing others (or attempting to do so, as discussed earlier) is wrong and from my viewpoint there is nothing that may justify that.

There's situations where killing is necessary in order to prevent greater harm, as unpalatable as that may be. If you've got a country in central Europe annexing its neighbours left and right there's only so many options before you either concede to their rule or resist.

Armies of different nations differ in what they do. That is to say some are just defensive, some engage in foreign assistance in addition to their defensive capacity. Foreign assistance from military forces can take non-violent forms. A person in the military can have combat training (i.e. be a "soldier") as well as qualified with other skills. For example, they could assist in reconstruction efforts in country X while defending civilians from country X's rebels or even serve in country Y in a totally non-violent capacity despite having combat training.

Consider a guy that goes on a rampage down town in Everycity. He's armed to the teeth and has made it clear there will be no negotiations. What do you do? Shoot his hands off? You often don't have time to mess about in such situations (or, in some cases, there's little chance of precision shots due to dense crowds, low visibility, etc) with civilians about, not to mention your fellow law enforcers lives in danger. This sort of thing can happen on an international or global scale. Yes, there are warning signs, and yes, if only this and that were done in the killer's or country's youth / history such tragedy could've been avoided. Unfortunately sometimes people inherit or are forced into a situation where diplomacy has failed.

Personally I'm strongly against war, foreign intervention, conscription and even voluntary enrolment in the army. That being said, each scenario needs to be assessed individually. An unwavering rule such as "we must never kill" is flawed in its general rationale as well as its specific dictate.