Over the past forty years, JWT has undergone both a revival and a renovation. Recent sophisticated versions of JWT, such as that developed by Michael Walzer in his influential book Just and Unjust Wars (1977), operate within the broad framework of JWT, but have secularised its substance. Biggar’s book is, in effect, an attempt by a Christian thinker to reclaim JWT from the secularists. It reinstates the explicitly Christian elements that have been omitted in more recent statements of JWT and then aims to show how this version can be applied to illuminate questions about the justification of particular wars, namely World War I and the Iraq War.

Biggar’s version of JWT is considerably more permissive than (what has become) the orthodox version. Firstly, following earlier thinkers such as Aquinas, he has a more capacious understanding of both the ‘just cause’ and ‘just intention’ conditions. Orthodox JWT now holds, consistent with international law, that the only just cause for war is a threat to peace, in particular military aggression. For Biggar, ‘what alone justifies belligerency is an injustice that is intolerably grave’, one that ‘calls for punishment’. Invasion and other threats to peace count as such injustice, but so can other kinds of action. So Biggar thinks that the atrociousness of Saddam Hussein’s régime, demonstrated by its murder of its own citizens, provided a just cause for going to war with Iraq, even if such atrocities were not occurring at the time that war was declared, and were not a threat to peace. For JWT, a just belligerent possesses ‘right intention’ when they fight only to rectify the wrong specified in the just cause. For orthodox JWT, this means fighting to restore peace (rather than, say, to gain territory). Biggar, on the other hand, sees war as a ‘punitive, retributive response to wrongdoing’, which should be ‘proportioned both retrospectively to the nature of the wrongdoing and prospectively to the goal of reconciliation or a more just peace’. Achieving such retributive aims may, of course, require going far beyond merely removing threats to peace.

‘Biggar’s book is, in effect, an attempt by a Christian thinker to reclaim JWT from the secularists.’

Secondly, Biggar relaxes the constraints which JWT places on justifying war. Orthodox JWT holds that even where there is a just cause for war, the decision to go to war can only be justified if there is a good reason to believe that the conditions of ‘success’ (the original wrong will be righted), and ‘proportionality’ (the good consequent on that success will outweigh the evils entailed in the fighting) will be satisfied. The rationale for these restrictions are obvious. Since violence is in itself a bad thing, it can only be justified when failure to use it would allow an even worse state of affairs to occur. Biggar, however, claims that the success and proportionality conditions are ‘merely supportive’: it is good if they can be satisfied, but a state may still be justified in going to war even if they cannot. In respect of ‘success’, he denies that a state must have good reason to believe that military action will succeed to be justified in launching it – ‘it might be right, indeed heroic, to fight against a very evil enemy with very poor prospects of prevailing’.

In the light of his theory, Biggar claims that the decisions by ‘our’ side to go to war in World War I and Iraq were justified – these were just wars. For JWT, whether a decision to go to war was justified depends on matters of fact, and Biggar engages in a detailed, subtle discussion of the historical record and its interpretation in support of his claims. In the case of World War I, he accepts a particular account of the highly contested history of the prelude to, and course of, that conflict. His discussion of the Iraq War, on the other hand, does seem even-handed.

Biggar’s claims about the justice of these wars, and more broadly his account of just war, are, in my view, deeply unpersuasive. Just war is, according to Biggar, a retributive act. Retribution involves coercive action that is proportional to the wrong to which it is a response, and directed to the agent responsible for that wrong, who thereby becomes liable to punishment. Neither of these conditions are satisfied in the wars that Biggar examines: it is doubtful, to say the least, that they can be satisfied in modern wars.

Consider World War I. A truly cataclysmic event, with some sixteen million people, seven million of them civilians, dying in its course, its malign political consequences, including the shattering of political units and the rise of totalitarian political forces, dominated the course of European history for decades afterwards. Some of this, of course, could not be predicted, but much of it, at least in broad terms, could be, and was, by the few sober minds among the political élite. In what sense was the war proportionate to the wrong of German aggression that, according to Biggar, justified the British decision to fight, a decision without which the effects of that aggression would have been so much less grievous? And on no reasonable understanding of liability could the vast bulk of those who bore the brunt of the war and its aftermath be seen as liable for punishment.

Similar points can be made about the Iraq War. More than 100,000 Iraqis have died in its course, the vast majority civilians. As a consequence of the ongoing inter-communal conflict unleashed by the US invasion in 2003, an estimated one in twelve Iraqi families have been displaced from their homes. The quality of life for all Iraqis has declined dramatically, with more than half of the nation’s doctors leaving the country after 2003: infant mortality has increased 150 per cent since then. Again, these consequences of the decision to initiate the war were, at least in broad terms, predictable. And again, virtually all of those who have suffered as a consequence of that decision were not liable for the harms inflicted on them.

Since modern war produces so much suffering for innocent bystanders, it is difficult to see that any war of the kind we are likely to confront could be justified on a retributive account such as Biggar’s. His attempt to provide a defence of war, in general and particular, is unsuccessful.