Unipolarity has attracted more scholarly attention than bipolarity ever did in its day. To offer one rough indicator, the online citation index Web of Science counts some thirty-eight articles in political science and international relations journals between 1990 and 2011 whose titles contain “unipolar” or “unipolarity.” A corresponding search for bipolarity yields only seventeen articles for the entire bipolar era from 1950-1989. That’s half the articles for twice the time. I am aware of some nine books devoted to the analysis of unipolarity but none wholly devoted to bipolarity. This attention is surprising, given widespread skepticism about the analytical utility of the very concept of polarity among political scientists. Indeed, Jeff Legro recently advised scholars to “sell unpolarity” as an “overused concept,” deploying arguments redolent of those levied against bipolarity a decade or two earlier.  And James Fearon lamented the fact that researchers bother to continue to debate unipolarity long after scholars such as Harrison Wagner developed such devastating criticisms of bipolarity.