The Real Issues of the Past 20 Years
Continuing on the topic of epistemic closure [still jumping off of reading the posts linked on Douthat's blog], here is my view of the four big developments of the past 20 years that should have influenced political thought of any ideology. The first is the fall of the Berlin wall and the collapse of the Soviet Union, the second is the rise of the EU, the third is the shift in power towards developing countries, and the fourth is our recent economic disaster. Discussing any of these is more appropriate to a book (or maybe series of books) and is part of a very wide ranging dialogue in academia, and to a lesser extent any other cultural outlet so I will not go into detail on them here.
I do think one of these however deserves a special discussion because of how the left and right reacted so differently to it, namely the collapse of the Soviet Union. Again doing a literature review of all the different reactions would take some space but the basic caricature of the right celebrating this event as a confirmation of their views as essentially correct and the left's celebrating this event as well but also seeing it as a time to reflect and reassess seems broadly correct. Any influence socialism had on liberal thinking declined remarkably. There was also probably a lot more work done by people on the left assessing the reasons for collapse, the broad consensus seems to be that collapse was driven by internal problems in the Soviet Union and its inability to deal with them within its current ideology.
While this remains a bit of a caricature, I have seen some on the right continue to hold the triumphalist view that we in some sense won, instead of the more common view that it is in fact them who lost and that they would have collapsed because their ideology simply didn't work, no matter what we did. The reassessment after this event is probably at least part of why the left has developed new ideas and approaches while the right's sense of triumphalism is one reason they may not have reflected as hard. What does surprise me is that this didn't cause both sides to reflect on what the collapse of the major power to attempt to govern itself by one of the three branches of 19th century political thought means. Let me restate this in a slightly childish way to emphasize how I believe this event should be viewed.
***RIGID ADHERENCE TO ONE OF THE GREAT 19TH CENTURY POLITICAL PHILOSOPHIES CAUSED THE IMPLOSION OF A GREAT POWER***
You can look at this in one of two ways. Either one of the other two political ideologies must be correct, or 19th century political and economic thought is incapable of dealing effectively with modern challenges, at least when rigidly adhered too. Rigid adherence to theory is incapable of sustaining economic and political development, ideology is simply insufficient as a governing philosophy. I think liberals took the second view more and have sought to adapt to a world that is less friendly to classical political theory and requires pragmatic reassessment and creative thinking.