Is the War against Iran a Just War?

What is a Just War - according to Augustine & Aquinas?

2026-03-13 by Steve Forkin

Christians and Conservatives alike, use the term 'just war' to justify current events, but rarely actually look at the sources they use to make their claims.

Is the War against Iran a “Just War” ?

Is “Just War Theory” a reasonable justification for the War against Iran?

Earlier this week I attended a mens Bible study group. We gather early in the morning to pray and study the Bible together. One of the men asked for prayer for his son who is in the Australian military. They have been advised to prepare for possible deployment. The agony this must cause for a parent..

After prayer the topic of “Augustinian, Just War Theory” came up. In my discussions with other Christians I have noticed that many will quote “just war theory” as a Christian or perhaps Conservative justification for war – despite their own reservations – and yet when pressed upon to give a proper definition, it becomes evident they only really know of the idea, but haven’t actually read any of the source materials.

In this post I want to dig a little deeper as to what, Augustine and later in the middle ages Aquinas defined as “Just War Theory”. The notion of “just war” is mostly used as an argument to support wars of aggression, where the act of aggression is against a pre-existing aggressor, even when this aggressor has not committed acts of aggression against the war initiating party.

The current US & Israeli war against Iran is one such example. Never mind the many claims by US politicians and media that Iran is really the aggressor and the US acted in self-defence. This is contra all facts. The US & Israel started the bombing campaign, they are the aggressors.

As an aside, one of the contributors to justifications for the wars in the middle east is the modern and novel theological system called Dispensationalism. Listening to the new administration in the US, it’s obvious where some of these men derive their “biblical ?” justifications for war. If you have ever wondered what to make of the famous Sermon of Jesus, known as the Olivet Discourse, I have written a book going into great detail, both biblically & historically as to why those chapters are primarily addressed to the church in the first century.

https://www.amazon.com.au/End-Beginning-Unmasking-Predictions-Discourse-ebook/dp/B0DPF23N29

It is up to those who put forward the argument of “just war” to give sufficient evidence – biblical when arguing from a Christian standpoint or philosphical/moral when arguing from a non Christian standpoint – in support of the claim that this war against Iran is just and the claim of “a just war” {according to Augustine & Aquinas} actually fits.

I personally think there is ample evidence in the New Testament to affirm that all wars of aggression are evil. I shall give a sample of references below and leave that to you the reader to decide for yourself how these passages should inform your views on war.

• Matthew 5:1-10, 20
• Matthew 5:39
• Matthew 26:52
• Romans 12:17

Whilst the New Testament does not explicitly tell us about self defence, there are examples of behaviour that give us strong clues of the right to defend oneself. See Paul’s response to being flogged in Acts 16:37-39.

My main desire in this post is to write about & hopefully clarify the notion called “just war theory” and the claim that the giants of philosophy, Augustine & Thomas Aquinas are sufficient for us to establish an argument in favour of the claim, that some wars of aggression are in fact just.

Some Christians really believe in “Solo” Scriptura, i.e. the Bible is there only moral authority. I believe in Sola Scriptura – yes the difference between “o” and “a” is really important here –, in the sense that the Bible is the final authority, but by no means the only authority. God gave the church great teachers, theologians and philosophers. To ignore them, is a form of ignoring scripture since scripture is the place where God tells us to listen to teachers!

Augustine, Bishop of Hippo (4th-5th century), quite literally lived through the collapse of the Roman Empire, by barbarian hordes. His works “City of God” and “Contra Faustum Manichaeum” are often quoted as source materials for his ideas about war and when war is just. I have personally read City of God, but not the other works. As to his other writings, I rely on source materials that are in public domain. You can easily search in them yourself.

If I am honest, I would say, any notions Augustine had about “Just War” are more like passing statements. To claim Augustine as an expert or someone whom we should look to for advice on this subject is at best a stretch. Since the advent of the internet no one can claim ignorance. All the writings of the Church fathers are in public domain and readily available.

Am not saying they are all easy to read or that we should not rely on, or look to historians for their interpretations, but sometimes it’s just right and wise to go to the source yourself and see! Isn’t that what Paul praised the Bereans for in the book of Acts? (Acts 17:11) That advise is just as valid for extra biblical source materials.

For the sake of not wanting to argue with an otherwise Great Theologian and Philosopher, maybe it’s fair to claim he laid some seeds that were later developed by others. Here are just a few of the quotes. I think you will agree with me that we are perhaps laying too much weight on his ideas, if we claim he is the expert:

“As if he would not all the rather lament the necessity of just wars, if he remembers that he is a man; for if they were not just he would not wage them, and would therefore be delivered from all wars. For it is the wrong-doing of the opposing party which compels the wise man to wage just wars; and this wrong-doing, even though it gave rise to no war, would still be matter of grief to man because it is man’s wrong-doing. Let every one, then, who thinks with pain on all these great evils, so horrible, so ruthless, acknowledge that this is misery.” (City of God, Book XIX)

“What is the evil in war? Is it the death of some who will soon die in any case, that others may live in peaceful subjection? This is mere cowardly dislike, not any religious feeling. The real evils in war are love of violence, revengeful cruelty, fierce and implacable enmity, wild resistance, and the lust of power, and such like; and it is generally to punish these things, when force is required to inflict the punishment, that, in obedience to God or some lawful authority, good men undertake wars, when they find themselves in such a position as regards the conduct of human affairs, that right conduct requires them to act, or to make others act in this way. Otherwise John, when the soldiers who came to be baptized asked, What shall we do? would have replied, Throw away your arms; give up the service; never strike, or wound, or disable any one. But knowing that such actions in battle were not murderous but authorized by law, and that the soldiers did not thus avenge themselves, but defend the public safety, he replied, ‘Do violence to no man, accuse no man falsely, and be content with your wages.’” (Contra Faustum Manichaeum, XXII)

These quotes so far haven’t established anything substantial in regards to whether it is right or justifiable to initiate a war, especially when one was not acting in self-defence. These quotes at best point to the fact that there are some possible situations or circumstances where war is the only option. As a Libertarian and Christian, I would suggest that self-defence is certainly one such circumstance, i.e. it is just and right to defend oneself against an aggressor.

“A great deal depends on the causes for which men undertake wars, and on the authority they have for doing so; for the natural order which seeks the peace of mankind, ordains that the monarch should have the power of undertaking war if he thinks it advisable, and that the soldiers should perform their military duties in behalf of the peace and safety of the community.” (Contra Faustum Manichaeum, XXII)

The claim that the Monarchy is part of the natural order, might have sat well in the 4th or 5th century, but that claim as we realise today has just as little substance as the claim made by many Christians today that God ordained the “modern state” and the use of Romans 13 to prove this is so. I challenge anyone to show me where in that chapter is a single reference to a monopolistic state as we have them today.

Please also note that Augustine claims the citizens should do military duties on behalf of the peace and safety of the community. This surely would only be true, if in fact the peace and safety of the aggressing nation was in jeopardy. If we are just trying to decide whether this new war against Iran is “just”. One thing is certain, at no point was a single member of the American community under any threat by Iran.

Romans 13 speaks of magistrates being ordained by God to reward good behaviour and punish evil behavior. Magistrates have existed during all forms of government in the last few millenia and hence there appears to be an untraverseable stretch from the role of a magistrate, who presides of every day court proceedings in modern democracies, all the way to a full blown modern state with an executive president, a police force, military and the gazilion long list of modern bureacratic offices that all appear to have and weild powers that ordinary citizens would land in jail for, if they ever dared to wield a single one of them.

Also, just in passing, in England starting with the Magna Carta in 1215, where the citizens were for the first time afforded the right to be tried by their peers, the office of a magistrate was held by volunteers, for a short period, chosen from the citizenry.

The idea that a “governing authorities == modern state” is as bad as calling an apple a banana! There was no modern state in Paul’s day, rather an Imperial Caesar – called Nero – who turned out to be the worst persecutor of Christians for centuries. Was Paul in fact endorsing Nero? I don’t think so. Context matters. The remainder of the first verses of the chapter clearly delineate what Paul actually had in mind when he use the term “governing authority”. The context suggests it is much more in line with what we know today as the “Civil Magistrate”.

For an in-depth theological and philosophical deep dive into Romans 13, I did my seminary masters thesis on this chapter & turned it into a book, which is available on Amazon. If you like the work I do, I would really appreciate if you could support my efforts by buying one of my books:

https://www.amazon.com.au/s?k=steve-forkin

Maybe we can sumarise Augustine’s views on “Just War” like this sylogism:

P1. Only a rightful ruler could declare a war. P2. To avenge a wrong, defend against aggression, or restore justice. P3. The motive must be love of peace, not hatred, cruelty, or greed.

C. When all these premises are met, a war, even a war of aggression can be classed as a “just war”

This is not my view, remember here I am just summarising Augustine. Next, we will look to see if the conclusion follows. Let’s further discount any false logic, i.e. let’s just assume that IF p1-3 are true, C necessary follows. I am not even sure it does, but I am giving the benefit of the doubt here.

Given the recent Epstein scandal that is drawing ever bigger circles in American and International politics, I find it really hard to believe in or justify any claim of “rightful rulership” at all, but let’s discount that argument and agree that the West has rightful rulers.

The question one must ask is this: “Is being a rightful ruler a sufficient condition for declaring a war?”. I would suggest that the original framers of the US Constitution had reasonable doubt about this, perhaps driven by their experience of the English Imperial Masters they sought freedom from. The US Constitution clearly suggests the power to declare war is vested in the US Congress. I my view, even the congress does not have the right to declare a war of aggression, i.e. the only true justification for war is self defence, but I digress. One thing is certain the executive office of the presidency in the US – by the US constitution – does not have the right to go to war, without congressional approval.

You may not agree, but what we can see here is that even Augustine’s premise 1 is at best wobbly and at worst not true! What I mean by “not true” here is that this premise fails when used to justify the current war against Iran.

Let’s look at premise 2. Augustine believed a just war falls into three categories. A, to avenge wrong. B, to defend against aggression and C, to restore justice. Frankly I see C as being a part of A and B, and A is almost the same as B. I would at least say premise 2 stands true, certainly when considering this mainly points to a war of self-defense!

Finally premise 3. The motive must be love of peace and cannot be hatred, cruelty or greed. If I take one look at the recent history of the Israeli war in Gaza, this was an epic fail of premise three. If I take just the first day of the war against Iran, then that war fails on this account too.

Could one possibly claim that bombing an entire school of children and teachers falls within the category of “love of peace”. Considering the claims by the US administration that this is just “collateral damage” and one must accept this in war, we could be done with this whole argument right here.

I don’t think there is a single one of the wars classified under the bucket term “war on terror” that actually passes the real “Just War Theory” test, and we have only looked at Augustine so far. None of them pass the smell test.

For a detailed analysis of the last few decades of the US “War on Terror” read Scott Horton’s book: “Enough Already”, he has all the receipts. He will leave you in no doubt at all!

https://www.amazon.com/Enough-Already-Time-End-Terrorism/dp/1733647341

Moving on then, let’s take a look at what St Thomas Aquinas wrote, who lived in the 13th century.

His Systematic Theology, magnum opuse called Summa Theologica, in the second part of part two has a chapter called “Whether it is always sinful to wage war?”. Again this is all in public domain. The chapter is an easy read. The Catholic church, who regards him as one of the fathers of the faith, has done a great job of making all his writings available to the public. As a reformed, protestant I too regard St Thomas as a giant of the faith. He, by no means, is owned by Roman Catholics.

https://www.newadvent.org/summa/3040.htm

Perhaps we can say that Aquinas distills Augustine’s ideas into a more precise structure, that I certainly would agree with, having read both in detail. In Summa Theologiae II–II, he writes:

In order for a war to be just, three things are necessary, we have called them the “The Three Classic Conditions for Just War”.

Again, please remember I am merely summarising what Aquinas has written, I am not saying I agree. I already pointed out what my view is biblically on this subject.

The Three Classic Conditions

1. Legitimate Authority:

“It is not the business of a private individual to declare war… the care of the common weal is committed to those who are in authority.”

2. Just Cause:

“A just cause is required, namely that those who are attacked, should be attacked because they deserve it on account of some fault.”

3. Right Intention:

“It is necessary that the belligerents should have a rightful intention, so that they intend the advancement of good, or the avoidance of evil.”

St Thomas also adds the following extra conditions:

• Proportionality: – violence must not exceed what is required for justice.
• Last resort: – all peaceful options must have been exhausted.

(Summa Theologiae, II–II)

It will be helpful to formulate this as a Sylogism to make this all more simple to follow:

• P1. War can only be initiated by those in proper authority
• P2. A just cause is required, either an act of self-defense, or the attacked must deserve the attack on account of a fault of their own
• P3. The motive behind the war, must be the advancement of good and or the avoidance of evil
• P4. Violent force used in the war, must not exceed what is required for the advancement of justice
• P5. All peaceful options must have been exhausted

C - If all premises are met, a war can be classified as just, even a war of aggression, not just an act of self-defense.

It’s quite obvious from this sylogism that Aquinas rested on similar ideas to Augustine, but appears to have fleshed them out in more detail. I would suggest, Aquinas actually intended to create somewhat of a doctrinal statement on the issue, whereas Augustine was simply referring to the notion, in no particular order.

I would suggest that given what we have today – as to wars in the middle east, certainly – not one single one of these premises are actually fulfiled and the people who use the justification “just war theory” in favour of the current war in Iran, have proven that they have either not really looked at the source materials, or chosen to simply use “just war” as slogan to silence debate. That may sound “harsh” but what other conclusion could one possibly come to once one actually looked at the cold hard facts?

In the case of the war in Iran, the proper authority – congressional approval – was not sought. The just cause simply does not exist. The notion that Iran has the capability to make nuclear weapons is as hollow as the “wmd” claims made to justify the war in Iraq. The motives behind the war – certainly this appears to be so to me – are really the Oil production and global trade wars. How is the “advancement of good” helped by dropping bombs on civilians – especially schools filled with children. Spare me the claims of collateral damage.

Peaceful options have by no means been exhausted, in fact the US administration was in the middle of discussions right when they decided to start the first bombing campaign. The US is in no place to lecture Russia about their war of aggression against Ukraine, and even that war has far more basis for justification than the war against Iran. The war against Ukraine should never have been started by Putin, but to suggest there was no “past” aggression by Ukrainians – armed by the US & the CIA – is ignorance. I digress.

We can perhaps sumarise or define Augustine’s and Aquinas’s views on Just War as follows:

“A war lawfully declared by rightful authority, in response to a grave injustice, with the intention to restore peace and justice, conducted with moral restraint and proportionate means.”

Using this definition as a filter for all the recent wars in the Middle East, one could suggest we are doing a gross injustice to both Augustine and Thomas Aquinas by using their ideas as justification for our wars. Both would reject wars for conversion, colonization, ideology, or vengeance.

I shall leave you with this final quote by Aquinas:

“True religion looks upon as peaceful those wars that are waged not for motives of aggrandizement, or cruelty, but with the object of securing peace, of punishing evil-doers, and of uplifting the good.” Thomas Aquinas.