Passed in response to the September 11 attacks, the Patriot Act grants law enforcement bodies in the United States greater authority in countering terrorism domestically and abroad. It amends previous laws, such as the Foreign Intelligence Surveillance Act, enhancing federal authority to track communications for intelligence and enforcement purposes, monitor borders, and combat money laundering operations.
This public law, 107-40 [S. J. RES. 23], was passed by Congress on September 14, 2001 and signed by President George W. Bush on September 18, 2001. The law authorized U.S. armed forces to use "all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001".