There are, however, practical political concerns in the United States that make the use of federal military forces less desirable for use in domestic law enforcement. Under the U.S. Constitution, law and order is primarily a matter of state concern. As a practical matter, when military forces are necessary to maintain domestic order and enforce the laws, state militia forces under state control i.e., that state's Army National Guard and/or Air National Guard are usually the force of first resort, followed by federalized state militia forces i.e., the Army National Guard and/or Air National Guard "federalized" as part of the U.S. Army and/or U.S. Air Force, with active federal forces (to include "federal" reserve component forces other than the National Guard) being the least politically palatable option.