How to have an ethical war

Thanks, Saturday Morning Breakfast Cereal, for this enlightening comic. Down with war!
Do Christians have the right to defend themselves? (Even from the state?)

This essay continues the Christian Theology and Public Policy Course by John Cobin, author of the books Bible and Government and Christian Theology of Public Policy. —- Do Christians have a right of self-defense? If so, under what circumstances may they defend themselves? May they only defend themselves against criminals or against civil authorities too? […]