The United States Army Intelligence Support Activity (USAISA), frequently shortened to Intelligence Support Activity (ISA), also known at various times as Mission Support Activity (MSA), Office of Military Support (OMS), Field Operations Group (FOG), Studies and Analysis Activity (SAA), Tactical Concept Activity, Tactical Support Team, and Tactical Coordination Detachment, and also nicknamed "The Activity" and the Army of Northern Virginia, is a United States Army Special Operations unit which serves as the intelligence gathering component of Joint Special Operations Command (JSOC). Within JSOC, the unit is often referred to as Task Force Orange. Originally subordinated to the US Army Intelligence and Security Command (INSCOM), it is one of the least known intelligence components of the United States military, tasked with clandestine HUMINT operations and collecting actionable intelligence during or prior to JSOC missions.

James Lee Dozier is a retired United States Army officer. In December 1981, he was kidnapped by the Italian Red Brigades Marxist guerilla group. He was rescued by NOCS, an Italian special force, with assistance from the Intelligence Support Activity's Operation Winter Harvest, after 42 days of captivity. General Dozier was the deputy Chief of Staff at NATO's Southern European land forces headquarters at Verona, Italy. The Red Brigades, in a statement to the press, stated the reason behind kidnapping an American general was that the U.S. and Italian governments had enjoyed excellent diplomatic relations and that Dozier was an American soldier invited to work in Italy, which justified their abduction. To date, Dozier is the only American flag officer to have been captured by a violent non-state actor.