At the end of the day, you need to sleep at night. I respect people who listen to their conscience.
Generals always prepare to fight the last war. As we move away from 20th century nation state conflict, that means the successor to the current counter-insurgency conflict. There's a pretty clear implication to that, which removes many of the comfortable abstractions that blowing up Soviet tanks came with.
There's a popular Quaker anecdote in the OP which is worth quoting in full:
"Many years ago, when William Penn converted to Quakerism and pacifism, he was troubled by the thought of having to give up the sword that he wore, a great honor at the time. He asked George Fox, the founder of Quakerism, what he should do. Fox told him, 'William, wear thy sword as long as thee can.'"
It's ultimately the choice of each individual to determine when they can no longer bear their sword.
Generals always prepare to fight the last war. As we move away from 20th century nation state conflict, that means the successor to the current counter-insurgency conflict. There's a pretty clear implication to that, which removes many of the comfortable abstractions that blowing up Soviet tanks came with.