The U.S. military expects to have 20,000 uniformed troops inside the United States by 2011 trained to help state and local officials respond to a nuclear terrorist attack or other domestic catastrophe, according to Pentagon officials. Critics of the change, in the military and among civil liberties groups and libertarians ... express concern that the new homeland emphasis threatens to ... undermine the Posse Comitatus Act, a 130-year-old federal law restricting the military's role in domestic law enforcement. The Pentagon's plan calls for three rapid-reaction forces to be ready for emergency response by September 2011. The first 4,700-person unit, built around an active-duty combat brigade based at Fort Stewart, Ga., was available as of Oct. 1, said Gen. Victor E. Renuart Jr., commander of the U.S. Northern Command. Two additional teams will join nearly 80 smaller National Guard and reserve units made up of about 6,000 troops in supporting local and state officials nationwide. All would be trained to respond to a domestic chemical, biological, radiological, nuclear, or high-yield explosive attack, or CBRNE event, as the military calls it. In 2005, a new Pentagon homeland defense strategy emphasized "preparing for multiple, simultaneous mass casualty incidents." In late 2007, Deputy Defense Secretary Gordon England signed a directive approving more than $556 million over five years to set up the three response teams, known as CBRNE Consequence Management Response Forces [CCMRF].