Brooks takes these general insights and explains why the international community has repeatedly failed to implement policies that are overall in everyone's interest (like trade liberalization). Contrasting the current situation to the immediate post-war period, Brooks argues:
Today power is dispersed. There is no permanent bipartisan governing class in Washington. Globally, power has gone multipolar, with the rise of China, India, Brazil and the rest.
This dispersion should, in theory, be a good thing, but in practice, multipolarity means that more groups have effective veto power over collective action. In practice, this new pluralistic world has given rise to globosclerosis, an inability to solve problem after problem.
Groups with a strong narrow interest are able to block larger groups with a diffuse but generalized interest. The narrow Chinese interest in Sudanese oil blocks the world’s general interest in preventing genocide. Iran’s narrow interest in nuclear weapons trumps the world’s general interest in preventing a Middle East arms race. Diplomacy goes asymmetric and the small defeat the large.
The current situation is indeed a 'tyranny of the minority' (in Olson's felicitous phrase) and a tragedy of the commons results as collective action on issues as diverse as global warming, trade liberalization, global security, environmental protection, space exploration and the protection of human rights falters.
So what to do? I agree with Brooks that John McCain's idea of a "League of Democracies" is a good start. Anomalies like 'rogue democracies' aside, liberal democracies (as defined by, say, Freedom House) have a lot of interests in common and, on Olson's logic, a subset of countries is much more likely to engage in successful collective action. Even if such a group is formed, however, vast problems will persist and national interests will be far from identical. I suspect, on current trends, that intergovernmental global governance will grow increasingly difficult, and thus supranational global governance will become increasingly necessary. But, of course, supranational institutions are exceedingly difficult to create and a global government is conceivable only in the very long run. The prospects for global collective action looks bleak for the foreseeable future.
(Brooks, by the way, has explicitly acknowledged he has been influenced by Olson, so I'm not reading too much into his column).