DynCorp, a security firm staffed by former military personnel, has received a billion dollar contract from the United States to provide four years of military training and advice to Afghan officials, as well as taking care of logistics and management of 14 Afghan military training facilities.
For over half a century, DynCorp provided technical services to the military, as well as aircraft maintenance for civilian airlines. But over the last two decades, DynCorp grew larger and more diverse supplying more services to the military. DynCorp personnel are found in places the U.S. is unwilling to send its own personnel. For example, DynCorp provides, at U.S. expense, logistics support for Ugandan peacekeepers in Somalia. DynCorp has been helping rebuild the Liberian armed forces. DynCorp has, for most of the past decade, been providing security teams for U.S. State Department personnel overseas (usually in very rough neighborhoods).
Over the last few decades, it's become increasingly common for private companies to hire retired military personnel to provide military training for nations the United States wants to provide those services for, but does not want to send American troops to do it. Aside from avoiding unwanted diplomatic and media attention, these firms have the advantage of hiring the most experienced and effective retired military personnel for training contracts. Many of these trainers served for years in the Special Forces, or otherwise established a track record as very effective trainers over a long period of time. Most of the trainers are recent retirees, thus they are in their late 30s or early 40s and in good physical shape. Because of their military experience, they work well with the NCOs and officers in any force they are dealing with.