John Haldane describes how it developed – and has continued to develop.
Well the historical … let’s start with the historical origins of the idea of just war. These, in the West – and there is no clear corresponding tradition in other cultures, I mean there are debates within other cultures about war, but it doesn’t look, as far as we know, as if there is a just war tradition outside of the West. And this in itself is actually maybe rather significant. Its origins in the West really lie in the fourth century, and in that period in which Christians have moved from being a small group – I mean obviously beginning as the Nazarenes, and so on, of being an oppressed group and so on – and have become a major presence within the Roman Empire. And of course, we get in the early part of the fourth century the conversion of the emperor, and so in a sense the empire is Christianised – at least insofar as its leader is. Now – and, you know, people could debate over how sincere was that conversion, there have been discussions about that, but that doesn’t really matter, what matters is that the head of state is now aligned with what had hitherto been an oppressed group.
Now some people think that his decision in that matter was precisely designed to put Christians in the position in which they would now have to fight for the Empire. Because Rome at this point is under threat, and there’s clearly an advantage in suddenly getting a whole new set of citizens who you could, as it were, enlist in the defence. And of course, if you’ve Christianised the Empire, they’ve now got a reason to defend it, right, because it is, as it were, a kind of instantiation of the kingdom or something of that sort.
So Christians are put in the position of being challenged: look, if you’re Christians, the emperor is Christian, the Empire’s Christian, you must defend it. And so debates begin about whether or not what has hitherto been the position of Christians, which is that they would … probably would not fight at all, so pacifism (but even if they’re not radical pacifists, they’re certainly not advocates of war), and now this challenge is put to them, you know, Christendom – not a term that’s used then, but will be used – Christendom is under attack, what are you going to do about it? So these discussions begin and we get in figures like Augustine some exploration of the question, under what conditions is it permissible to use violence? And in particular, to lend yourself to the use of violence on behalf of a state or a polity or a city or whatever else it may be.
And I think that what’s interesting is what you get then is a line of argument that says, well look, people have a right of self-defence, individuals have a right of self-defence. There’s nothing either in the Hebrew scripture or in the Christian Testament that prohibits self-defence. Given that you may have a right of self-defence, you probably also have a right to defend those who can’t defend themselves – people for whom you have a responsibility, your immediate family or community and so on – so what we can see building up here is a right of self-defence. But it was always part of the Christian conception that there is the inviolability of the innocent, right – that you may defend yourself but you may not, as it were, slaughter others in the process of doing so.
And in fact in Aquinas, if we leap forward, you know, almost a thousand years, Aquinas actually says in his account of these matters that you may not intend lethal violence, even against an attacker. So you may use violence in defence of yourself or those for whom you have responsibility, but you may not, in the process of doing so, intend the death of the attacker. Now of course it may be that what you do results in the death of the attacker, it may even be that you foresee that is likely to result in the death of the attacker, but you may not make the death of the attacker part of your purpose. And so that really comes from … so it’s this idea of the inviolability of the innocent gives you both a right to self-defence on the one hand, right – to protect, and protect those for whom you have responsibility – but on the other hand a constraint on the use of violence, that one must always be … have regard for human life, even the life of an attacker.
So what you then get sort of developing in the 16th century is there are more elaborations around this: notions of proportionality, in terms of bad effects; that violence should be a last resort; it should only be used in circumstances in which there is a legitimate authority directing its use, and so on. So you get the build-up of a kind of doctrine, a just war doctrine.
I would just – if I may just add one thing that has happened in our own lifetimes that I think is quite significant as a departure from this, is that it was always a feature of the just war doctrine that at its core is, if war is permissible, it’s only in the circumstances of defence. Right, so there may be no aggressive wars. Now that’s been … pressure’s been put on that from two directions. One is the idea of pre-emptive wars. So if you could … if you haven’t yet been attacked, but you anticipate that you may be attacked, maybe you use violence though no violence has yet been used against you. And I would say the traditional just war doctrine is going to have some difficulties with pre-emptive attack.
In terms of recent politics a new idea has sort of come on the scene, the advocates at the political level of which were Tony Blair and George W. Bush. And that is the idea of wars of humanitarian intervention. So this is deploying the resources of the state, or perhaps an alliance of states, to actually initiate a war – not pre-emptively to defend yourself, or not in response to attack upon yourself, but actually to intervene where some other set of people are subject to attack or whatever else it may be, or, you know, deprived by their regimes or whatever else it may be.
Now the interesting thing about that is we could discuss – and no doubt there will be further discussions of that – but that is not compatible with traditional conceptions of just war. And it’s quite interesting because in the case of Tony Blair and George W. Bush, they’re both Christians, and I think Blair would have seen himself – believed himself – to be espousing a policy of just war. But in fact those wars would not be just in terms of classical Christian understandings. And not only Christian understandings, but the understandings that were developed out of those Christian understandings. And it is worth saying that there is no tradition of just war thought in the West that arises independently of the Christian tradition.