All change at the top of US forces in Afghanistan as the US seeks a change of direction in its war on al-Qaeda.After less than a year in the job General David Mckiernan returns home and is replaced by the current head of the joint Chiefs of Staff General Stanley McChrystal. With a new ambassador arriving among several other changes the Pentagon denies their approach has not worked “With agreement on a new strategy and a new mission and national and international approach in Afghanistan we felt that if there was to be a change then this is the right time to make that change,” says Defence Minister Robert Gates. McChrystal faces a difficult situation. In several weeks there is a presidential election, and despite troop reinforcements the terror threat remains high. With Afghanistan now top priority he will be in the firing line himself if things get worse.