Post-Civil War Act Prevents Military From Guarding Buildings or Making Arrests.

By YOCHI J. DREAZEN

The federal government's response to one of the nation's worst natural disasters has been complicated by a law from the aftermath of the Civil War.

With looting reported in parts of the storm-ravaged Gulf Coast, the military announced plans to send 30,000 National Guard troops to help local police departments protect buildings and arrest looters and rioters. Active-duty troops could have been deployed more quickly to do those tasks but aren't allowed to guard critical buildings like hospitals or confront looters because of restrictions imposed by the Posse Comitatus Act of 1878.

After the Civil War, the Army was deployed throughout the South to maintain civil order, enforce Reconstruction policies and prevent lingering political resentments from flaring into open violence. Public discomfort at the sight of federal soldiers at political rallies and polling places led Congress to pass the act, which bans the military from direct participation in law-enforcement roles like making arrests. Subsequent court cases cleared the way for active-duty troops to perform support or humanitarian tasks.

The law doesn't apply to the National Guard, a point commanders made repeatedly yesterday in trying to put to rest rumors that martial law had been declared in some of the worst-hit areas. Lt. Gen. Steven Blum, who commands the reserve troops, said only National Guard troops would be used in law-enforcement roles in cities such as New Orleans. "This is not, as has been erroneously reported, martial law," Gen. Blum said.

The strictures of the law have been eroded by the demands of the nation's campaigns against drugs, illegal immigration and terrorism. Beginning with the Reagan administration, active-duty Navy and Air Force personnel have been used in the war on drugs, and thousands of active-duty military personnel are routinely deployed at high-profile events like the 1996 Atlanta Olympics or the Super Bowl to help prevent a terrorist attack.

Legal experts said if conditions along the Gulf Coast continue to deteriorate, policy makers could use an exception to the law -- the Insurrection Act -- that lets governors request active-duty forces during periods of severe public disorder. That is how active-duty personnel were allowed to help quell the Los Angeles riots in the early 1990s and the Chicago riots of 1968.

"In situations where it's impossible otherwise to enforce the laws of the U.S., active-duty troops can be used to suppress violence and restore law and order," said Scott Silliman, a Duke University professor who specializes in military law. "You could certainly make the case now that they're needed in New Orleans."

It was unclear if active-duty personnel would be formally requested, but some policy makers made clear that they were seeking help wherever it could be found.

"I've actually asked for uniformed troops of any sort," Louisiana Gov. Kathleen Blanco said. "I have just gotten word that we'll get as many troops as we need for as long as we need. I've asked for 40,000."