Try Reading Ministry of Defeat by Richard North it makes painful reading but it does give the full anaylsis as to how the British Army was stabbed in the back through poor equipment and a general lack of willpower amongst politicians and the MOD to push for victory.
When Blair agreed to take Britain to Iraq he wanted a repeat of the Gulf War a quick victory then instant exit that he could take the credit and secure his reputation. When the reality proved far from his liking he sought to Iraqify Basra and the surrounding areas as quickly as possible as the campaign become more unpopular at home.
So while the Insurgency grew British forces shrank, the final blow came when Brown became prime minister because the campaign was so unpopular by then his first priority on taking over was to end it as soon as possible.
The British army was never allowed to truly get to grips with the insurgency if they had done a surge of their own things may have been different but neither the goverment or the MOD had the will to do that.
I can't wait to see the headlines in the papers tomorrow. It's a good job no journos read ARRSE. Oh, hang on.......