In Christian thinking about war, there have been two main strands: just war and pacifist theory.
Pacifism commits its adherents to a refusal to collaborate with, or give support to, any war.
The position can be grounded in two ways: its adherents can argue either that all war today is intrinsically immoral or that, despite the reasonable arguments in favour of war, the specific teaching and example of Jesus Christ forbids his followers to take part in it.
Many are attracted to pacifism because it is radical and uncompromising. They may also disdain just war theory as a device for allowing those set on war to maim and kill others, while also enjoying a good conscience and reputation. Both the form of argument endorsed by just war theory and its conclusions are, according to pacifists, inconsistent with Christian faith.
Pacifism is often a powerful, mute challenge to the national conscience. But public discussion will be the poorer if it is the only Christian contribution. For if pacifism is grounded in the example of Jesus Christ, it will be able to engage only with Christians, leaving others to get on unchallenged with the making of war. If pacifists argue that all war is immoral, they need to argue their case.
Public argument and conversation are important, because they allow arguments to be scrutinised. They also demand that arguments apply equally to similar cases. The reasons that allow or prohibit us from going to war will also allow or prevent our enemies from doing so.
A recent statement by the United States bishops accepts the importance of public discussion. Because it is pitched within the public debate, it offers a framework for moral conversation without drawing definitive conclusions. It uses the categories of just war theory in a way that shows awareness of their frequent misuse:
Just war teaching has evolved … as an effort to prevent war; only if war cannot be rationally avoided, does the teaching then seek to restrict and reduce its horrors. It does this by establishing a set of rigorous conditions which must be met if the decision to go to war is to be mostly permissible. Such a decision, especially today, requires extraordinarily strong reasons for overriding the presumption in favor of peace and against war.
The categories of just war theory, namely proper authorisation, just cause, hope of success and proportion between good and evil caused, offer a shorthand list of questions that