Reluctant Warriors: Christianity and the Just War Tradition

By Jason Carlson

How are we as Christians to rightly live in a world of war? This has been a question that followers of Jesus Christ have wrestled with from the very earliest years of the Christian faith. This question was recast in many Christians’ minds this past week as we struggled with the reality of a prominent Christian leader advocating the assassination of another country’s President. However, even prior to those comments, many Christians have grappled with the reality of America’s “war on terror” and our military actions in Afghanistan and Iraq. What are proud Americans who give their ultimate allegiance to the Prince of Peace to think about these matters?

God’s word, the Bible, provides some important insights into the reality of warfare and our proper Christian view and response towards it. Let us briefly note three key Biblical teachings related to warfare:

1. From scripture we recognize that warfare is a reality that God has condoned, participated in, and will participate in again in the future (Exodus 15:1-18; 17:8-15; Numbers 31:1-3; Deuteronomy 2:26-31; 3:1-7; 20:1-4; Joshua 5:13-6:27; Revelation 6:1-2; 19:11-21; 20:7-10). Thus, if our good, holy, and perfect God has sometimes condoned and participated in warfare, no matter how much we may dislike it, we cannot say that all warfare is inherently evil.

2. In Exodus 20:13, the sixth commandment admonishes us, “You shall not murder.”  What’s interesting to note about this commandment is that it is only directed against murder, the wrongful taking of another human life. Scripture assumes a distinction between murder and certain other forms of killing, such as capital punishment or warfare, which the Bible allows for (Genesis 9:5-6; Exodus 21:12-14).

3. In allowing for certain other forms of killing, God has ordained human governments, not private citizens, as the agents of justice, retribution, rewards and punishments (Matthew 5:38-39; Romans 12:17-13:7; 1 Peter 2:13-17). Thus, God has given governments the charge to perceive when military action is necessary.

Using these Biblical realities and teachings, Christians throughout the centuries have formulated some guiding principles as to how and when human governments may rightly participate in warfare; these principles have become known as the “Just War Tradition”. Two of the earliest church fathers that attempted to reconcile the individual Christian’s call to live peaceably with all, while living under human governments and often having to serve in their nation’s military, were Ambrose of Milan and Augustine of Hippo (circa 300’s A.D.). Their “Just War” positions have remained the majority Christian viewpoint since the fourth century A.D. Following their lead, other prominent Christian theologians who have expounded on the Just War Tradition include: Thomas Aquinas, Martin Luther, Ulrich Zwingli, and John Calvin.

The Just War Tradition historically focuses on eight guiding principles for determining when human governments may rightly engage in warfare. These eight principles are summarized as follows:

1. Just Cause – The only justifiable war is a defensive war. Wars of aggression, started for the purpose of gaining territory, promoting an ideology, or acquiring wealth are not considered just.

2. Just Intent – The objective of a defensive war must always be the restoration of peace and the defense of innocent human life.

3. Last Resort – All efforts at peace, negotiation, and compromise must have failed. Waging war should never be the first option.

4. Formal Declaration of War – Only a properly authorized authority can declare war and a formal declaration of war must be clearly stated.

5. Limited Objectives – Since peace is the ultimate goal of a just war, the unconditional surrender or total destruction of an enemy are not legitimate objectives.

6. Proportionate Means – The weaponry used in warfare and the degree of force must be limited to what is necessary to secure a just peace.

7. Noncombatant Immunity – The use of force should discriminate between combatants and noncombatants. Civilians and prisoners of war should be guaranteed immunity.

8. Reasonable Hope for Success – A defensive war against aggression must have a reasonable hope of securing peace for it to be considered just.

These eight principles summarize the essential elements of the Just War Tradition. Once again, the Just War Tradition has been the majority Christian viewpoint on warfare throughout the history of the church. This does not mean that the Just War position is absolutely correct, but it does lend much weight to its credibility for the discerning Christian.

While the reality of warfare is one of the tragic consequences of living in a fallen and sinful world (Genesis 1:31 & Genesis 3; Romans 1:18-32), God promises us that a day is coming when “Nation will not take up sword against nation, nor will they train for war anymore” (Micah 4:3). We will have to wait for the coming reign of the “Prince of Peace” to see that promise fulfilled here on Earth (Isaiah 9:6; Revelation 21 & 22). Until that day comes, the best hope for human relationships is to follow the model of Jesus Christ, the ultimate example of living a life of peace. However, in those sad chapters of human history when warfare and terror are thrust upon us, the Just War Tradition provides a moral compass that can rightly guide all reluctant warriors into battle.