AOG
My knowledge of military strategy is nil, but I should think that, that would be a good question for a final examination for an officer cadet at Sandhurst..
But at a guess:
What is the enemy strength?........probably known 8yrs ago
What armament do they have? ...IED have been the most effective.
How can we neutralise their armaments? Taken a long time to realise how deadly the IEDs are.
How many troops on the ground do we need to achieve our objective? At the start if the campaign, the Americans and Brits with help from the Canadians and Germans provided the basis of troops on the ground, the strike force mainly contributed by the American and Brits...........clearly it was felt that more troops were needed and it took time to convince the particular countries to "chip in" more troops.
Could a smaller but mobile force do the trick? ...clearly not and it took time to make this obvious.
Not a very good answer AOG, but others will provide a more valuable and informed input.