The American Civil Liberties Union wants to know why the Pentagon has assigned a fighting unit to the United States itself. On October 1st, the Northern Command, for the first time ever, got its own dedicated Army force. The unit the Pentagon assigned to NorthCom is the 3rd Infantry, First Brigade Combat Team, which has spent three of the last five years in Iraq. One of its specialties is counterinsurgency. This is a radical departure from separation of civilian law enforcement and military authority and could, quite possibly, represent a violation of law, said Mike German, ACLU national security policy counsel. Our Founding Fathers understood the threat that a standing army could pose to American liberty, he added. German also noted that Congress has passed statutory protections to ensure that the Army could not be turned against the American people. The ACLU is seeking documents from the Justice Department, the Pentagon, and Homeland Security that authorize the deployment of military troops for domestic purposes. United States Northern Command is a Unified Combatant Command of the United States military. Created on October 1, 2002 in the aftermath of the September 11th attacks, its mission is to protect the United States homeland and support local, state, and federal authorities. The support that NorthCom provides to civil authorities is limited by the Posse Comitatus Act, which limits the role of the U.S. military in civil law enforcement