They chose a profession that they knew might put them in a situation of killing innocent people.

But a profession that is necessary in order for the country to survive. Someone has to do it, otherwise the country would be susceptible to the whims of whatever foreign power deems its conquest worthwhile. They stepped up to fill that vital societal role. We shouldn't be disparaging them because of the actions of some idiots many of them didn't even vote for but that the majority of the country did.