Grotius had discussed punishment because he was concerned with justifications for war. If punishment had not been relevant to war, he would not have discussed it. However, as Luban points out, the idea that punishment is a justification for war faded from intellectual discussion in the twentieth century (even while it surely persisted in the culture at large).
Luban has two aims, one historical and the other philosophical. His historical aim is to chart the movement from accepting punishment as a cause of war to rejecting it. His philosophical aim is to argue that punishment is not actually an acceptable justification for war.
Here is his thesis.
“I provisionally accept retributivism, but I shall argue that even for retributivists punishment through warmaking is morally unacceptable for at least five reasons: (1) It places punishment in the hands of a biased judge, namely the aggrieved party, which (2) makes it more likely to be vengeance than retributive justice. (3) Vengeance does not follow the fundamental condition of just retribution, namely proportionality between punishment and offense. (4) Furthermore, punishment through warmaking punishes the wrong people and (5) it employs the wrong methods. Regardless of the intuitive pull of the punishment theory, modern international law was right to reject it.” (2012, 305)
In other words, he accepts a retributive theory of punishment in general but believes it cannot be used to justify war.
In my opinion, Luban’s five points can be collapsed into two:
I said that the first point is true of all causes of war. The desire to punish is often characterized as being overly emotional and not fully rational. But, as Dani pointed out, when states go to war in self-defense, they are typically motivated by fear and fear rarely produces completely clear thought. So punishment may be a bad justification for war, but it is not obviously worse than all of the others.
Maybe that’s the right conclusion. Maybe none of the justifications for war that make sense in an ideal world could be adequate in the real world since those making decisions cannot be relied on to apply them correctly. But I was under the impression that Luban was arguing for something narrower than pacifism. I thought he wanted to show that punishment is an especially bad justification for war.
The second point struck me as more compelling. Wars harm people too indiscriminately to be justified as punishment of the guilty.
Luban argues that punishment could make sense as a justification for war only if everyone in the country being attacked is collectively guilty of whatever bad behavior is being punished by the war. But this kind of collective responsibility for a state’s behavior does not make any sense, he claims, and so this is not a defense of using war for the sake of punishment.
Luban, David. 2012. “War as Punishment.” Philosophy and Public Affairs 39 (4): 299–330.
There was a handout for this class: 21.Luban.handout.pdf