TAM O’ Shanter perched atop his head, pistol secured in its holster on his belt, steel-rimmed glasses pushed back on to the bridge of his nose, Lieutenant-Colonel Mike Riddell-Webster, the commanding officer of the Black Watch, is striding through the crowded market place in the centre of the town of Az Zubayr. Yesterday, this street was thought still too dangerous to drive down in a soft-skinned Land Rover, but the CO has decided - enough is enough. After days of sitting back and watching his troops come under attack from militia men armed with mortars, AK47s and rocket-propelled grenades, he...