Major world events, such as the Arab Spring of 2011, the fall of communism just over 20 years ago in Eastern Europe and the Soviet Union, and the financial crisis of 2007-09, sometimes come as a complete surprise to almost everyone. It is of course important to try to understand such events, but it is sometimes not easy to know how even to begin to analyse them.

August 2011 has seen days of rioting in London and other cities in the UK. In Spain, demonstrators known as indignados recently occupied town squares and demanded a full-scale change of the political system. And Greece continues to see violent clashes between the police and demonstrators protesting against round after round of budget cuts.