Just a thought - as yet unformed, but I wanted to acknowledge and record it.
Pacifism - resolute non-violence - rests on the refusal to act in a way which is sinful (that a violent action is sinful is not disputed).
The church's role is to cultivation and form disciples in such a way that this becomes second nature, that it governs the way that they think about these things.
Sometimes the consequences of acting in this sin-less manner (or less sinful manner) is that great harm is achieved within the world by those who have chosen violence. World War II is the classic example. Non-violent resistance did not/ would not dissuade the Nazis.
There is, therefore, a claim implicitly being made here, that the 'eternal' consequences justify the temporal costs.
This, it seems to me, is a form of world-denial. I am not sure how to reconcile this with an incarnational faith.