Sovereignty, Intervention, and Justice

Is military intervention ever justifiable – if so, when?

Justice between individuals is something we aspire to, or should aspire to. We should seek to treat others justly. And justice within a nation is also a social good that we affirm, although we often fail to achieve it. And justice between nations in the international community is also a vital good.

Justice, peace and order are all important social goods that we strive for in these three arenas. Because we live in a fallen world made up of selfish sinners, these things are needed, but they also seldom live up to the expectations that we put on them. Thus injustice, conflict, and disorder are usually the norm instead of the exception.

But the fact that such social virtues are never fully realised or achieved does not mean we should not work toward them. And here I want to look at the third arena, that of international relations and geopolitics. How can we maintain justice among nations?

Indeed, when we consider the nation state and the notion of sovereignty, how does talk of things like intervention fit in? Is it ever right for one nation to interfere in the affairs of another nation, be it militarily, economically, or politically?

Entire libraries exist to discuss these mega-topics, and many disciplines come into play here including politics, ethics, law, history, theology and philosophy. So this of necessity will be a very brief and skimpy introduction to these issues. Many more articles will be needed to tease these matters out in more detail.


The modern nation-state arose during the 17th and 18th centuries. While nations have long had concerns about political and territorial integrity (think of ancient Israel and its clearly defined borders for example), the modern nation-state especially gave rise to the notion of national sovereignty.

The 1648 Peace of Westphalia laid out the principle of sovereignty whereby states could expect to be free from external control. Paul Miller discusses how the Westphalian tradition differs from the Augustianian tradition:

Justice, in this view, did not include liberality or charity; it involved the protection of rights – not human rights, but the rights of sovereigns. Above all, in this era, international justice became equated with the rights of sovereign autonomy and the reciprocal noninterference associated with the treaties of Westphalia.”

Thus today the notion is widespread that we must adhere to the inviolability of state borders. But modern international law has acknowledged the obligation of nations to offer protection and humanitarian aid to those victimised by armed conflict and natural disasters. The 1863 Geneva Convention for example speaks to this, as do later conventions.

Some thinkers hold to national sovereignty as some sort of absolute. When it comes to war and international relations, the realists (eg., Carr, Reinhold Niebuhr, Morgenthau, Kennan, and Kissinger) take this view, stressing the importance of non-intervention.

It is those who hold to versions of just war theory who see a place for intervention. They rightly ask,Can a nation become so barbaric and tyrannical to its own citizens, and so belligerent and threatening to other nations, that some sort of armed intervention becomes prudent and morally acceptable?’

Taken further, is there ever a place for preemptive war? For example, would the world have been far better off with far fewer people killed had the Allies not waited until Hitler had taken large portions of Europe before acting? Might a first strike earlier on have prevented not just massive bloodshed, but the Holocaust as well?

All these questions have been debated at great length and cannot be entered into here in any thorough fashion. But the notion of intervention as a means of keeping the peace, preventing injustice, and maintaining some order and stability in the world is something that we need to carefully think about.


If national sovereignty is a key principle of today’s international order – sacrosanct for some – how and when might intervention occur, if at all? Questions like this have been with us quite a long time, especially in the form of just war thinking. The need for self-defence or defending justice that comes under assault are key reasons why the use of military force can be moral. See more on this here:

While modern international law disparages offensive wars, and seeks a no-first-use rule, certain preemptive or interventionist actions can still be granted morally justifiable status. Various ethicists, philosophers and theologians have sought to make that case.

It was the church father Ambrose of Milan who famously said in “On the Duties of the Clergy”: “He who does not keep harm off a friend, if he can, is as much in fault as he who causes it.” This can apply not just to individuals but to nations. To help defend a nation under attack or on the receiving end of injustice can rightly justify the intervention of others.

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Morality and Contemporary Warfare by Johnson, James Turner (Author) Amazon logo

And these principles, as many have pointed out, are often for the good of a third party. As James Turner Johnson put it, “What is most fundamental in this conception of just cause is that it justifies the use of force not out of self-interest but for the sake of others: those who are in need of defense or who have suffered wrongs needing to be righted.

This is an important point for the Christian, and one that I have raised elsewhere. Often a Christian will argue that we must simply turn the other cheek when attacked as per the instructions of Jesus. But as I have explained, the willingness to put up with a personal insult is one thing, but that does NOT preclude coming to the aid of a third party.

If someone insults me, I can just move on. But if someone tries to attack my wife or children, I have every moral and Christian right to come to their defence. That is the loving thing to do. See more on this matter here:

Let me very briefly mention two major just war thinkers on the matter of intervention. Michael Walzer in his classic 1977 work Just and Unjust Wars offers three main reasons for such intervention: 1) intervention in certain civil wars, to assist in secessionist movements; 2) counter-intervention in a conflict to offset prior intervention by another power; and 3) intervention to counter extreme violations of human rights, eg. those threatened with massacre.

And Paul Ramsey said this in his 1968 The Just War: “It is simply an illusion to believe that there exists or can exist a system of impenetrable nation-states, founded upon an absolute principle of non-intervention, which has removed from among the decisions of magistrates the question whether the political good will be sustained more by intervention or by non-intervention.”

So a number of important thinkers argue that if there is a place for individuals to intervene in the face of aggression or injustice to another person, the same principle can be applied to nations. There may well be a place for intervention – even military intervention. Of course we often lack fully clear mental and moral guidelines here. Most conflicts are messy and somewhat ambiguous.

We can ask when is a just war – as defined by the traditional criteria – actually and properly taking place? In a fallen world there will be no perfect and pristine just war, just as there will be no perfect and pristine anything. Determining if and when military intervention is warranted will always be a complex and difficult question to answer.

And then we also have related issues such as the possibility of just revolution. Is there ever a time and place for a justifiable revolution? Many Americans would obviously think that the American Revolution was just. But see more on this question in this two-part article:

As mentioned, this is just a bare-bones introduction to a number of related and important questions. Forthcoming articles will look at these matters in much more detail, so stay tuned.

For further reading:

There are 85 or so volumes I featured in a recent article on what to read about war and peace:

And I recently penned a piece on intervention:

Here are a few more specific places to turn to:

Paul Miller, Just War and Ordered Liberty. Cambridge University Press, 2012. See ch. 4, “The Westphalian Tradition.”

Paul Ramsey, The Just War: Force and Political Responsibility. Rowman & Littlefield, 1968, 2002. See ch. 2, “The Ethics of Intervention.”

James Turner Johnson, Morality and Contemporary Warfare. Yale University Press, 1999. See ch. 3, “The Question of Intervention.”

Michael Walzer, Just and Unjust Wars. Basic Books, 1977. See ch. 6, “Interventions.”

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3 Replies to “Sovereignty, Intervention, and Justice”

  1. Does the invention of weapons of mass destruction alter the arguments? In Europe we seem to be fighting a proxy war against Russia. Both NATO and Russia can reduce each other’s cities to what one commentator calls “glass-lined car parks”. Considering the character of the people who have the power to initiate this, we pray for God’s mercy.

  2. Thanks John. You raise several points that all can be turned into full-length articles in order to properly answer them. But a few short answers. Some have tried to argue that the just war tradition is no longer useful or relevant in the atomic age and in the age of total war. Whether we are speaking of high-yield conventional weapons, or nuclear weapons, the tradition is said to no longer be sustainable. But a few things can be said.

    It has been argued by many that the only use of nuclear weapons so far (to end WWII) was in fact ethically justified as it actually saved lives, and so on. But see more on this here:

    And here:

    And then there are now different payloads (mega-tonnage and so on) available for various weapons and bombs. Some can level a very small country, some a small city, and some a small structure. Things like biological weapons are condemned both by just war criteria and international law. Cluster bombs and other devices also can be questioned in terms of just war thinking.

    And much modern weaponry (eg computer guided smart bombs, cruise missiles etc), using conventional (ie., non-nuclear) payloads or warheads, are far more precise and accurate today. Instead of dropping large bombs from a plane and hoping they will more or less hit a target without causing too much collateral damage, we can now send a missile into a window or an air vent of a building, taking out precisely the target we are aiming for. So various criteria such as proportionality and non-combatant immunity seem to be actually strengthened and enhanced in modern warfare – if it is used rightly.

    And one can talk about the possession of nuclear weapons as a deterrent. In theory (and so far in practice) this has meant no new world wars breaking out. And part of this for some decades has included things like the doctrine of Mutually Assured Destruction, the idea that launching a nuclear first strike would be far too costly for the side considering it. Thousands of articles and hundreds of books now exist seeking to deal with such matters. As just one example of how a just war theorist might respond, see this representative but somewhat older piece by William O’Brien on “Just-War Doctrine In a Nuclear Context”:

    As to how to further think morally and even Christianly about nuclear weapons, see the section on this matter found in this reading list:

    And as to Putin’s rape of Ukraine, no we are not fighting Russia as such, we are seeking to defend a sovereign nation from Putin’s aggression. And Putin’s invasion of Ukraine does not tell us that just war theory is useless or dead, it just tells us that basically all the core principles of just war theory are being violated by Putin as he commits was crimes there. So Putin is to be condemned, not traditional just war thought.

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