In public, defeat in Afghanistan is unthinkable for western governments. In private, for many it already seems inevitable - at least if the western definition of "victory" remains the vastly overblown goals set since the overthrow of the Taliban, within any timeframe that is likely to be acceptable to western electorates.

In recent meetings involving Nato officials I have been struck by the combination of public acknowledgment that, to achieve real and stable progress in Afghanistan, western forces will probably have to remain there for a generation at least, and deep private scepticism that western publics will stay the course for anything like that long. Indeed, most plans have the hopeless aim of producing clear results within three years, for fear that otherwise Canada will not prolong its presence beyond 2011 and the whole Nato effort will begin to unravel.