Does “just war theory” justify war?

One response »

1. John Hooker says:

   May 5, 2026 at 5:11 pm

   There seems to be a widespread impression that just war theory is a theory that justifies war.  Actually, it justifies war only under very strict conditions.  The war with Iran comes nowhere near meeting these conditions. 

   Just war theory is not a single theory, but a body of related thought on when a war is just.  Most of the ideas originate with the Christian scholars Augustine of Hippo and Thomas Aquinas.  There are different interpretations, but the consensus today is that just war theory justifies war only when 6 conditions are met:

   • It is a war of self-defense against an attack that is underway or imminent.  The Iran war clearly fails this condition, since there was no attack, and no credible evidence of an imminent attack.

   We need go no further, because the Iran war is already disqualified.  But we can consider the other conditions for the sake of argument.

   • The war is a last resort after all peaceful means have been attempted.    It is unclear what the Iran war was intended to accomplish in the first place, and so it is difficult to judge whether all peaceful means had been exhausted.  If the goal was to prevent Iran from developing nuclear weapons, the 2015 Joint Comprehensive Plan of Action demonstrated that a peaceful approach can work.  Unfortunately, the U.S. unilaterally withdrew from the agreement in 2018 despite Iranian compliance.  Subsequent attempts to revive the deal failed (due in part to fear the U.S. would renege again), and one might claim that these attempts exhausted all remaining peaceful means. Maybe, but this requires argument.  One must also show evidence that Iran actually intended to develop nuclear weapons, despite its denials. 
   • The war is declared by a sovereign state rather than a private militia.  This condition is met.
   • The war should have the right intention.  This is generally taken to mean that the war should not be for the sole or primary purpose of national aggrandizement.  This condition is difficult to check, since as already noted, it unclear what the intention was.
   • The war should have a reasonable chance of success.  Multiple experts warned that the war would escalate without achieving any clear goals.  This has been confirmed by subsequent events.
   • Finally, the end should be proportional to the means.  If the end was to prevent Iran from developing nuclear weapons, and there was clear evidence that Iran intended to do so, then one can argue that an attack on military facilities was proportional.  The attack must meet all the above conditions, however, and it did not.

   It is not my purpose to defend classical just war theory, but only to apply it to the Iran war.  However, the ethical framework I use in this blog leads to a related (and much simpler) conclusion.

   The autonomy principle is usually the deciding factor.   It forbids interference with another person’s freely chosen actions without implied or informed consent.  This does not rule out interference with unethical actions, because an unethical action is not autonomous.  The principle therefore allows self-defense.  I can forcibly stop someone from mugging me. 

   However, I can’t ethically kill the assailant to stop the mugging, because death interferes with many perfectly ethical actions. 

   What if killing the assailant is the only way to save my life?  Then I violate the autonomy principle no matter how I respond.  It is impossible to exercise autonomy at all, and I am reduced to an animal with survival instinct. 

   This is how it is in war.   The combatants are forced into kill-or-be-killed situations and must respond out of instinct or prior conditioning.   Self-defense is neither right nor wrong, but morally equivalent to an involuntary reflex. 

   Putting individuals in this position is itself destructive of autonomy.  If there is any nonlethal means of avoiding war, the autonomy principle demands it.  If not, both sides are compelled to sacrifice their humanity.

   LikeLike

   Reply