Some commenters on my earlier post arguing that international law should not consider genocide a more severe crime than other types of mass murder argue that genocide is worse because it targets victims based on immutable characteristics, such as race and ethnicity. This is a common argument. But I don't think it works.

First, the current international law definition of genocide is not in fact limited to immutable characteristics. It includes targeting of victims based on religion, which is most certainly not immutable.

Second, and far more important, many mass murders that are not genocide under current international law also target people based on immutable characteristics. For example, communist regimes routinely target people based on their economic class origins. Obviously, you can't do anything to change the fact that your parents were "bourgeois" or "kulaks."

Even in the case of targeting based on characteristics that can be changed, it is often too late to change them at the time the mass murder occurs. For example, my great-grandfather was arrested by the NKVD (as the KGB was then called) in the 1930s for having attended speeches by Leon Trotsky years before. At the time he went to the speeches, such attendance was not only legal but actually encouraged by the communist government, since Trotsky was a high-ranking Party leader. Years later (after Stalin had his rival Trotsky exiled and executed his most prominent supporters), such attendance became a crime punishable by a term in a Gulag (which often resulted in death). There was no way that my great-grandfather could have foreseen this at the time he decided to attend Trotsky's speeches. Fortunately, he was able to persuade the NKVD investigator that he really hadn't attended the speeches in question (although he actually had been present). A great many others were not so lucky.

Finally, even if the current definition of genocide really did capture a neat divide between mutable and immutable characteristics, I don't see why the mutable-immutable distinction should carry any moral weight. Killing a person because of his political affiliations wrong; so is killing a person because of his race or ethnicity. I don't see why the latter is somehow more wrong than the former merely because political affiliations can be changed and racial ones can't. The key question, it seems to me, is whether the killers are justified in demanding such a change as the price of allowing their victim to live. If not, their actions are just as reprehensible as murder based on characteristics that the victim can't change. If future technological developments allow people to rewrite their DNA and thereby change their race, would racially-based mass murder become less reprehensible than it is today? I think not.