Posse Comitatus Act


'Posse Comitatus' is a Latin phrase meaning "force of the county" and is a law in the USA.

For a good many of us, our understanding of the 'Posse Comitatus Act of 1878' stipulates that the US military can not operate 'militarily" on USA "soil". Well, this is not exactly a full understanding.

When first passed it ONLY referred to the US Army - no other military branch was included.

In 1956 the US Air Force was included in the Law.

The US Navy and the US Marines have a similar restriction; but, it is restricted by a DoD directive - i.e., not the "Law" itself. Obviously a directive can more easily be rescinded than a Law.

The US Coast Guard is not covered by any such restriction or law.

The National Guard operates under the applicable state(s) authority. If called upon by the Federal Government, the National Guard becomes, in a temporary fashion, part of the US Army or US Air Force.

In fact, the Posse Comitatus Act doesn't really restrict domestic action by the military. It just requires an act of Congress or fall within the US Constitution's governance to do so.

For those interested in the actual Law, click here.The Posse Comitatus Act of 1878

For a good many if us the 'Posse Comitatus Act of 1878' stipulates that the US military can not operate on USA "soil". Well, not exactly.

When first passed it ONLY referred to the US Army - no other military branch was included.

In 1956 the US Air Force was included in the Law.

The US Navy and the US Marines have a similar restriction; but, it is restricted by a DoD directive - i.e., not the "Law" itself. Obviously a directive can more easily be rescinded than a Law.


The below article addresses the Posse Comitatus Act in a little more detail:

The Posse Comitatus Act is the United States federal law (18 U.S.C. 1385, original at 20 Stat. 152) that was passed on June 18, 1878, after the end of Reconstruction. Its intent (in concert with the Insurrection Act of 1807) was to limit the powers of local governments and law enforcement agencies in using federal military personnel to enforce the laws of the land. Contrary to popular belief, the Act does not prohibit members of the Army from exercising state law enforcement, police, or peace officer powers that maintain "law and order"; it simply requires that any authority to do so must exist with the United States Constitution or Act of Congress. In this way, most use of the Army and the Air Force at the direction of the President does not offend the statute, even though it may be problematic for political reasons.

The statute only addresses the US Army and, since 1956, the US Air Force. It does not refer to, and thus does not restrict or apply to, the National Guard under state authority from acting in a law enforcement capacity within its home state or in an adjacent state if invited by that state's governor (in its federal capacity, the National Guard forms part of the Army or Air Force of the United States). The Navy and Marine Corps are prohibited by a Department of Defense directive (self-regulation), but not by the Act itself.[1][2] Although it is a military force,[3] the U.S. Coast Guard, which now operates under the Department of Homeland Security, is also not covered by the Posse Comitatus Act, primarily because the Coast Guard has both a maritime law enforcement mission and a federal regulatory agency mission.