This video says about itself:
With their existing armies overstretched, Britain and America rely heavily on mercenary forces. In Guns For Hire: Afghanistan, former war reporter Sam Kiley investigates the shadowy world of the modern soldier of fortune.
Thursday’s warning by Afghan President Hamid Karzai that US and other NATO troops could be regarded as “invaders” in his country provided a rare glimpse into the political realities in Afghanistan—and called forth a furious reaction from the Obama administration and the American media: here.
No joke: Karzai threatens to join the Taliban: here.