In a recent post, I noted that 2013 had distinguished itself in a dismal way, by producing more new episodes of mass killing than any other year since the early 1990s. Now let’s talk about why. Each of these mass killings surely involves some unique and specific local processes, and people who study in depth the societies where mass killings are occurring can say much better than I what those are. As someone who believes local politics is always embedded in a global system, however, I don’t think we can fully understand these situations by considering only those idiosyncratic features, either. Sometimes we see “clusters” where they aren’t, but evidence that we live in a global system leads me to think that isn’t what’s happening here.