A "just war" – if there could be such a thing – would not require conscription. Volunteers would be plentiful.
An Open Letter to President Wilson (October 14, 1919) by Ben Salmon
Regardless of nationality, all men are brothers. God is "our Father who art in heaven." The commandment "Thou shalt not kill" is unconditional and inexorable. … The lowly Nazarene taught us the doctrine of non-resistance, and so convinced was he of the soundness of that doctrine that he sealed his belief with death on the cross. … When human law conflicts with Divine law, my duty is clear. Conscience, my infallible guide, impels me to tell you that prison, death, or both, are infinitely preferable to joining any branch of the Army.Ben Salmon
Either Christ is a liar or war is never necessary, and very properly assuming that Christ told the truth, it follows that the State is without [in the words of Father Macksey] ‘judicial authority to determine when war is necessary,’ because it is never necessary.Ben Salmon