Jeff McMahan on What Rights Can be Defended by Means of War

On the evening of Thursday 7 February, Jeff McMahan, Honorary Fellow of the Oxford Uehiro Centre for Practical Ethics and Professor Philosophy at Rutgers University, delivered an insightful and fascinating Astor Lecture at the University of Oxford.

McMahan’s topic was the relatively underdiscussed question of the extent to which states are morally entitled to resist what he called ‘lesser aggressors’, who are seeking not to take over the state in question or to inflict major harm or damage, but some lesser goal, such as control over some relatively insignificant piece of territory. McMahan mentioned the Argentinian invasion of the Falklands Islands as a possible example. 

Of course, almost everyone will accept that, in at least some cases of lesser aggression, a state is entitled to defend itself. The question is one of proportionality. Perhaps the UK was morally permitted to send the forces it did send to the Falklands. But what if it had had to kill 50,000 Argentine combatants to defeat their invasion, or if defensive action would predictably have killed 5000 Argentine civilians as a side effect? As McMahan pointed out, international law has remarkably little to say on this question, and philosophers have tended to speak of proportionality in relation to lesser aggression of one individual against another rather than within just war theory.

McMahan notes that, outside war, killing in response to lesser aggression will often be impermissible. And it should not be forgotten that the harms of lesser aggression may be very small, or even non-existent, for each citizen, or that in war innocent bystanders will often be killed or seriously harmed. War can cause spirals of aggression, making things worse for all.

And of course combatants will also be killed or harmed, and McMahan argues that there should be restrictions even here. Nor need we think that partial loss of sovereignty is analogous to a person’s losing a limb. It may not do any harm at all.

Nor can one appropriately compare lesser aggressors to Derek Parfit’s ‘harmless torturers’, who each inflict a tiny harm on many individuals, with the result that these individuals suffer a great deal. In lesser aggression, as mentioned above, the resulting harms are often small or non-existent.

But so-called ‘wide proportionality’ (that concerned with those not liable to be killed, non-combatants in particular) does allow for the aggregation of small harms to large numbers of people, so that in some cases large harms to lesser aggressors may be permitted. And it should be remembered that lesser aggression is often backed by a threat to inflict much greater harm. Lesser aggressors are usually more like muggers than mere thieves. And lesser aggressors, if they succeed, may often seek to take more, and then more, and … So McMahan defends a ‘moderate’ position in response to lesser aggression: it is sometimes permitted, but only within limits.

What about deterrence? It’s hard to demonstrate the effectiveness of any particular threats, whether carried through or not, and when major retaliation is threatened this may encourage lesser aggressors themselves to up the ante, by, for example, the use of innocent shields.

An animated discussion followed the lecture, in which several real-life cases were discussed, including the Gulf War and the US invasion of Iraq. I wondered myself whether states might not prefer international law to include norms of proportionality that would result in the minimization of harms. So if it turned out that threats of massive retaliation, carried out when necessary, were in fact effective in minimizing such harms, such threats and such retaliation should be legally permissible.

(I am grateful to Jeff for comments on a earlier draft of this summary. A podcast of the lecture may soon be available via ABC Radio in Australia, which plans to broadcast it. We may provide a link to that podcast or upload our own.)

  • Facebook
  • Twitter
  • Reddit

Comments are closed.