A common criticism of private military contractors is that their employees - typically former Marines, SEALs, Rangers or other special forces - receive extensive training from the government, only to then move to the private sector where they can make more money. But a recent Washington Post article explains that Blackwater trains not only trains US law enforcement authorities, but also Army and Navy personnel. So it turns out that the folks moving to the private sector received their training... in the private sector. Go figure.
Perhaps more to the point, the critics of private security contractors fail to realize the nature of these men. In the special operations community, men usually stay operational for a small duration after which the command assigns them to staff work. Instead of languishing at a desk, many soldiers and sailors retire from the military not just to make more money, but also to return to the battlefield: the place they've been trained to be, the place were they belong.