The US Military is not allowed to act as a military against its own people.
There was a huge article about this in the Army Times. As of October 1st, the 1st Brigade Combat Team of the 3rd Infantry, was deployed here in the USA.The First Raiders will spend 2009 attached to the U.S. Northern Command. They will be based in Fort Stewart, Georgia, and focus primarily on logistics and support for local police and rescue personnel.
The Posse Comitatus Act was passed in 1878. In 2006, President George W. Bush pushed Congress to pass the John Warner National Defense Authorization Act, which included a section titled “Use of the Armed Forces in major public emergencies.” This section provided that “The President may employ the armed forces to restore public order in any State of the United States the President determines….” In effect, this bill obliterated Posse Comitatus.
When Congress passed the 2008 National Defense Authorization Act, however, the restrictions of Posse Comitatus were restored. But when President Bush signed the Act into law, he attached a signing statement (Executive Order) indicating that the Executive Branch did not feel bound by the changes enacted by the repeal. Hence, Posse Comitatus no longer exists.