This has long been a matter of debate. In very broad general terms, my impression is the use of following justifications:
Esp. for Roman Catholics, Augustines doctrine of a “Just War”. So attacking an enemy for shit and giggles (or profit for industry) is not ok, defending the life of civilians when somebody invades your territory is acceptable.
(How much that applies to the last conflicts, and how it applies when taking part in a larger Alliance like NATO or UN, or how to invade a country to stop a massacer against civilians like Ruanda, is obviously a matter for lot of debate. But theoretically you can use that logic as good defense, just as you can point out why this specific case doesn’t meet the requirements.
The “pastoral” * approach: We as Christians are opposed to war, but we recognize that war will happen, and when people involved in it need spiritual care, we will help in our position as pastors (mostly the position of the Lutheran / Protestant Church here).
Obviously, there’s a difficult line to walk between “as christian opposed to war, I would need to try and convince every doubting soldier who comes to me to oppose the war, which would be sabotage of morale etc.” and “as part of the military/ agreeing that this specific war is a necessary smaller evil than doing nothing, I must convince every doubting soldier who comes to me to go back to the front”
I think that the old M.A.S.H series shows both Father Mulcahey (who is Catholic, but helps all faiths as best as he can and knows) and Psychatrist Friedmann as caught between “real help for the soldiers would be to send them home” vs. “War must go on”, while still being very helpful and understanding.
As long as pastors volunteer for this and are not ordered to, I assume they have found a way to reconcile the different aspects of their faith with the military.
Though I don’t know how many reconsider and quit seeing real war up close, or judging that Military in general might be necessary, but that they can not support this specific War because of following reasons.
- In my native language, literally Soul-care.