If there is a just war, does the Bible give instructions for how this war should be carried out?
And if any mischief follow, then thou shalt give life for life, Eye for eye, tooth for tooth, hand for hand, foot for foot, Burning for burning, wound for wound, stripe for stripe.Exodus 21:23-25
First, war must be fought with proportional force. This is not to say that we have to handicap our soldiers, but that we do not nuke a country for the killing of one of our citizens. We are seeking justice not vengeance. If we are seeking to end injustice we cannot perpetrate it. As such, our rules of engagement will be different than our enemies. If we sink to their level we have become just as unjust as they are.
And Joshua saved Rahab the harlot alive, and her father’s household, and all that she had; and she dwelleth in Israel even unto this day; because she hid the messengers, which Joshua sent to spy out Jericho.Joshua 6:25
When thou comest nigh unto a city to fight against it, then proclaim peace unto it. And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, that all the people that is found therein shall be tributaries unto thee, and they shall serve thee. And if it will make no peace with thee, but will make war against thee, then thou shalt besiege it: And when the LORD thy God hath delivered it into thine hands, thou shalt smite every male thereof with the edge of the sword: But the women, and the little ones, and the cattle, and all that is in the city, even all the spoil thereof, shalt thou take unto thyself; and thou shalt eat the spoil of thine enemies, which the LORD thy God hath given thee.Deuteronomy 20:10-14
The soul that sinneth, it shall die. The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.Ezekiel 18:20
The conquest of Canaan is a different topic for another time. Essentially God was using the nation of Israel to judge idolatrous nations, and He wanted to ensure that there would be no vestige of idolatry left to tempt the Israelites. There is no modern day equivalent for Christians because the people of God is now not confined to national heritage. We must be careful to distinguish between Israel’s conquest of Canaan and our duty as Christians today. However, we can learn much from God’s instructions in the Old Testament.
One thing that is clear from these passages is that we cannot support that killing of non-combatives. We must protect innocent life at all costs. We must seek to avoid civilian casualties. We cannot become like those who move from justice to vengeance and hate. The killing of the families of our enemies should be soundly condemned by Christians. We are opposed to the taking of innocent life. Period. We are prolife! That means we oppose abortion and the killing of Afghan children. Non-combatives are off limits.
When thou shalt besiege a city a long time, in making war against it to take it, thou shalt not destroy the trees thereof by forcing an axe against them: for thou mayest eat of them, and thou shalt not cut them down (for the tree of the field is man’s life) to employ them in the siege: Only the trees which thou knowest that they be not trees for meat, thou shalt destroy and cut them down; and thou shalt build bulwarks against the city that maketh war with thee, until it be subdued.Deuteronomy 20:19-20
Lastly, a just war must have limited objectives. We are not seeking the annihilation of a land. We are not seeking to destroy an entire country and make it uninhabitable. That is what ISIS does, not Christians. If you do not destroy a nation you do not have to engage in nation building. Our objective is justice and the defense of human life. As such Christians should oppose the complete destruction of a nation’s infrastructure. Obviously there will need to be some level of disrupting communications, etc. However, things like Sherman’s march to the sea during the Civil War where he burned everything in his path is completely contrary to everything in Christianity.
So in conclusion. For a Christian to be able to engage in a war it must meet seven criteria:
- Legitimate authority with a formal declaration of war (Romans 13, power of the sword, etc.)
- Just cause (justice or the defense of human life
- Just intent (justice, restoration of peace, not vengeance)
- Last resort (all options for peace have been exhausted)
- Just means (protection of innocent life, non-combatives)
- Proportionate means (justice not vengeance)
- Limited objectives (justice, restoration of peace not total annihilation)
Any war that does not meet these criteria should be opposed by Christians. Christians should disobey any order to participate in any unjust war.