The last 2 major conflicts that we have been involved in (Iraq and Afghanistan) have been very similar, in that the Allies planned and exercised the military takeover very well and swept in quite efficiently. However, winning the initial war was the easy part. Winning the 'hearts and minds' has proved far more difficult - especially when you are dealing with a population with VERY strong tribal and religious cultural ties with morals that are so different from our own.
We went into Afghanistan to find Bin Laden - who was eventually found in Pakistan. Surely, with all the technology we have in the west, we could have taken him (Bin Laden) out using a drone, or a small SAS raid, without the need for a full-scale invasion followed by a long, expensive occupation?
But....as I'm neither a politician nor a military man what do I know?