Hurricane Katrina revealed the need for a much better ability to respond to the possible catastrophes — natural or man—made — which may hit our major cities. On Thursday, September 15, in the wake of Katrina, President Bush said:  

'It is now clear that a challenge of this scale requires greater federal authority and a broader role for the armed forces — the institution of our government most capable of massive logistical operations on a moment's notice.' 

But you can't do that, opined columnists and pundits.  Any broader role for the armed forces would violate the Posse Comitatus Act. And then with the assuredness of a gambler with aces up a sleeve, they would cite that Act: 

'Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.'  (Title 18, U.S. Code, Section 1385) 

Simply put:  a president is barred by law from deploying federal troops to the several states in a law enforcement role. That is why President Bush asked Governor Blanco of Louisiana to mobilize the Louisiana National Guard and formally ask for federal assistance, only to have her demur for 24 hours.
The phrase posse comitatus, translated from Medieval Latin, means 'power or force of the county.'  Derived from British Common Law, it refers to a body of men whom a sheriff can raise to help keep the peace.

But the act does completely forbid the use of federal forces domestically. There are a number of exceptions.  It doesn't apply to: 

1. The U.S. Navy and Marine Corps, even though both have acted as if it did for decades;

2.  The U.S. Coast Guard, formerly a component of the Department of Transportation and now part of the Department of Homeland Security, is both a law enforcement and military agency;

3. The National Guard when under gubernatorial command as state troops; 

4.  The National Guard when called to federal active duty, e.g. the 1950s to '60s civil rights unrest, Democrat Party Convention rioting and the Watts riots;

5.  Military personnel assigned to military police, shore police, or security police duties. 

And it does not prevent the president from deploying federal troops to quell riots or civil disturbances. From 1795 to 1995, as Colonel John R. Brinkerhoff states in his excellent essay 'The Posse Comitatus Act and Homeland Security:

'Federal troops have been used over 200 times in the two centuries from 1795—1995 — mostly to enforce the law and many (times) to enforce state rather than federal law.' 

Another authoritative source, Bonnie Baker's November 1999 essay "The Origins of Posse Comitatus" (published in Air and Space Power Chronicles) states:

'The Posse Comitatus Act contains legal loopholes by exception, 'except in such cases and under such circumstances as such employment of said forces may be expressly authorized by the Constitution or by Act of Congress.' These exceptions provided a loophole by which Posse Comitatus has been suspended several times in this (20th) century, including the use of federal troops to end the rioting in Chicago in 1919, against the Bonus Marchers in Washington, DC in 1932, and under the Truman administration when a railroad workers strike was ended by nationalizing the railroads and placing them temporarily under the Army Corps of Engineers.'

In his October 2000 essay 'The Myth of Posse Comitatus' posted at the Department of Homeland Security website, Army Reserve Major Craig T. Trebilcock notes that

'Congress has also approved the use of the military in civilian law enforcement through the Civil Disturbance Statutes: 10 U.S.C. sections 331—334 (which) permit the president to use military personnel to enforce civilian laws where the state has requested assistance or is unable to protect civil rights and property.  In case of civil disturbance, the president must first give an order for offenders to disperse.  If the order is not obeyed, the president may then authorize military forces to make arrests and restore order.' 

The author goes on to say that the scope of these statutes is broad enough to encompass disturbances resulting from 'terrorist or other criminal activity.'

In addition, there is the Stafford Act, 42 U.S.C., Section 5121, which allows federal troops to be deployed in times of natural disaster at the request of a governor, as President Bush requested of Governor Blanco. Under this Act a president may declare a major disaster and send in forces on an emergency basis for up to 10 days to preserve life and property. 

'In the past five years,' writes Trebilcock, 'the erosion of the Posse Comitatus Act has continued with the increasingly common use of military forces as security for essentially civilian events.' 

He cites the deployment of over 10,000 troops to the 1996 Olympic venues in Atlanta under the 'partial rationale that they were present to deter terrorism' then notes that

'The use of active duty military forces in a traditional police security role did not raise any serious questions under the act...'  (Italics mine)  The Posse Comitatus Act, notable for these exceptions, has been cited recently in reaction to President Bush's Jackson Square, New Orleans Katrina aftermath speech.  There can be no doubt that he believes it is time to change it.

As Brinkerhoff tells us in his essay, it was President Franklin Pierce's attorney general Caleb Cushing who

'blessed the posse comitatus doctrine and opined that marshals could summon a posse comitatus and that both militia and regulars in organized bodies could be members of such a posse.' 

Why did Attorney General Cushing opine thusly?  To help enforce the 1850 Fugitive Slave Act. The operative effect  of his opinion meant that Army units under their own commanders could still be pressed into service by marshals or sheriffs as a  posse comitatus without the president's approval. In practical terms, it allowed the Army to assist local law enforcement out in the wild West, or where they were the only personnel who could enforce the law.  As Brinkerhoff stresses, this was merely Cushing's opinion. It had not yet undergone judicial or legislative review. 

The 1866 Civil Rights Act allowed U.S. marshals to utilize the posse comitatus of the counties, or portions of the land or naval forces of the United States, or of the militia, validating the role of federal troops who were effectively governing the 11 defeated Confederate states during Reconstruction.  Before the Civil War, as Brinkerhoff writes,

'the militia under state control was used to control local disorders throughout the United States, but during Reconstruction, there was no effective militia in the defeated States, so the Army protected the people (especially newly emancipated slaves) and dealt with disturbances.' 

In 1878 Congress, having grown tired of marshals habitually employing Army troops without presidential authorization, passed the Posse Comitatus Act, which passed as an amendment to the Army appropriations bill.  Here, Brinkerhoff stresses that

'Congress voted to restrict the ability of U.S. marshalls and local sheriffs to conscript military personnel into their posse.  They did not vote to preclude the use of troops if authorized by the president or Congress.' (Italics mine)

'Greater federal authority and a broader role for the armed forces,' is what President Bush now wants Congress to consider in the aftermath of Katrina. And he wants Congress to know that he believes he has the executive authority to deploy troops should an emergency or catastrophic situation require doing so. 

Given the Swiss cheese nature of the old Posse Comitatus Act and the multitude of exceptions to it, it is now time to discard it and write a new law for the 21st century. It is time to begin discussing how to preserve our liberties from the type of threat of military domination experienced by so many other countries, while at the same time allowing us to respond to domestic emergencies arising from acts of God like hurricanes and earthquakes, as well as the man—made threat of terror attacks. The time to debate the issue is now, not in the federal courts following a future disaster, when we will have our hands quite full.

John B. Dwyer is a military historian and a frequent contributor to The American Thinker.