Put it this way: When the anniversary articles come to be written on 11 September 2031, will commentators look back on a 30 years war against Islamist terrorism, comparable to the cold war, as the defining feature of world politics since 2001? I think not. They will most likely see this longer period as being defined by the historic power shift from west to east, with a much more powerful China and a less powerful United States, a stronger India and a weaker European Union.