A Holy Soldier?

"When you go out as a camp against your enemy, you shall be careful about all bad things" (Devarim 23:10). The Torah goes on to discuss regulations of purity and of hygiene and explains, "For Hashem, your G-d, is going in the midst of your camp to save you and to hand your enemy over to you, and your camp shall be holy, and He shall not see in you an unseemly thing and abandon you" (ibid. 15).
Judaism does not mandate any action that justifies the breaking of boundaries of basic order. To the contrary, the more important a course of action is the more care must be taken to do it in a way that it is not dirtied or spoiled. If the enemy’s army camps are a place where anything goes and semblances of humanity disappear, the Torah way is that our camp must be a holy one. "A soldier" and "holy"? In today’s mind-set, the sound of the two together is strange. However, that is only because the general mind-set is so far from the concepts of the Torah.
The whole concept of war is a different one for us. For the nations, it is a time of wholesale murder, without rules or a search to justify one’s actions. An outburst of the animal within a person, of the basest instincts, is considered a good thing for them. That way the wild soldier can act with greater cruelty and less thought. Judaism does not allow murder. For us, war is designed to fight those who have already lost human dignity, so that their destruction is a removal of evil. This mitzva must be done in a way that uses no less holiness and purity than any other mitzva.
"He who is afraid and is of a soft heart," who is sent back from the camp (Devarim 20:8), is referring to one who is afraid due to sins of which he is guilty (Sota 8:5). It is possible that there is no such concept among the nations of the world. Perhaps it is to the contrary for them, one who breaks through boundaries may be stronger and braver than others. However, this is not the case for Israel. We are nourished by our connection to Hashem, and one who sins severs this connection, which causes him to be afraid. The apparent bravery that he might display comes from fear, and it can be the trigger to his subsequent fleeing from the battle. It is only the bravery of those who already have nothing to lose.