And yet the evidence is now overwhelming that on all fronts, despite inevitable losses from time to time, it is we who are advancing and the enemy who is in retreat. The current mood on both sides of the Atlantic, in fact, represents a kind of curious inversion of the great French soldier's dictum: “Success against the Taleban. Enemy giving way in Iraq. Al-Qaeda on the run. Situation dire. Let's retreat!”

Since it is remarkable how pervasive this pessimism is, it's worth recapping what has been achieved in the past few years.