"With the current operations tempo for Federal forces, the availability of manpower for homeland security is a major concern. Today's missions are full spectrum: traditional operations in Iraq and Afghanistan, peacekeeping in the Balkans and the Sinai, and defense support to civil authorities during hurricanes Katrina and Rita. President George W. Bush's National Security Strategy makes it clear that defending our Nation against its enemies is the first and fundamental commitment of the Federal Government. With the gradual reduction in force and increased deployments, however, commanders are asked to do more with less. As troops engage in overseas operations, for example, they are tasked with additional short-notice contingencies that further exacerbate the problem. Given the needs of the Department of Homeland Security and U.S. Northern Command, the increased use of National Guard and Reserve units, and the many and varied asymmetrical threats confronting the Nation since 9/11, it is questionable whether sufficient forces will be available. Therefore, a serious study of expanding the use of legitimate volunteer military organizations is long overdue. These groups are not new in America and are divided into state and Federally sponsored organizations. State-sponsored organizations include State Defense Forces (SDFs) and Naval Militias, while elements such as the U.S. Air Force Civil Air Patrol and the Coast Guard Auxiliary are sponsored by the Armed Forces."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/
State Defense Force Journal (Fall 2006), v.2 no.2, p.3-11