Reading Room Document

Authority for Use of Military Force to Combat Terrorist Activities Within the United States

The opinion determines that the president has both constitutional and statutory authority to deploy the military against terrorists operating within the United States. The opinion also determines that deploying troops domestically is consistent with the Posse Comitatus Act, since it was intended to prevent only the use of the military for domestic law enforcement purposes, not military purposes. It further concludes that the Fourth Amendment does not apply to domestic military operations against terrorists; even if challenged in court, the opinion concludes that the military operations would satisfy the Fourth Amendment's reasonableness test. The OLC does not provide release dates for its opinions, so the release date listed is the date on which the opinion was authored. The original opinion is available at https://justice.gov/olc/docs/memomilitaryforcecombatus10232001.pdf.

October 23, 2001