For Americans, it's a jarring sight: Uniformed soldiers, armed and dangerous, patrolling the train stations of New York, the bridges of San Francisco Bay and the streets of dozens of cities in between.
It's a sight common in much of the rest of the world, but one that American leaders as far back as the Founding Fathers have scrupulously tried to avoid except in disaster areas and desolate stretches of the U.S.-Mexican border.
Now, it could become even more common.
A handful of U.S. senators and some in the Bush administration are calling for changes in a 150-year-old statute, known as the Posse Comitatus Act, that keeps the military out of the business of domestic law enforcement.
"We've got to figure out a new Posse Comitatus that allows the Department of Defense to step forward and defend America," insists Georgia Democrat Max Cleland.
The talk is pricking the ears of civil libertarians everywhere.
"We don't want the militarization of civilian life," said Todd Gaziano of the conservative Heritage Foundation in Washington, D.C.
"There are obvious needs in a natural disaster or other emergencies that might necessitate some temporary assistance, but otherwise local police control is important," he added.
Congress passed the Posse Comitatus Act in 1878 to end military occupation of the Reconstruction-era South. As originally written, it prohibits the armed forces from enforcing civil laws "except in cases and under circumstances expressly authorized by the Constitution or Act of Congress." The language was intended to echo the Founding Fathers' distaste for a standing federal army watching over Americans at home.
Since its passage, courts have interpreted the law to allow the military to provide equipment, training and facilities to local, state and federal law enforcement. To go beyond that, though, the president must declare a national emergency — a bio-terror attack, for example, or an insurrection or natural disaster.
Presidents have set aside the act several times, most recently in 1986 when the National Security Decision Directive authorized soldiers to patrol the borders for drugs. In 1992, 4,000 members of the Army and Marine Corps joined National Guardsman in Los Angeles to quell the riots that followed the acquittal of police accused of beating Rodney King.
It is when these police actions end in violence — and they did in 1997, when Marine drug patrols on the southern border shot and killed a young goatherd — that questions arise about whether soldiers are better suited to war than civil service.
"The danger is they are not trained properly in confronting civilians," noted Tim Lynch, director of the Project on Criminal Justice for the libertarian Cato Institute in Washington, D.C.
"Military people are not known to be thinking about the Constitutional rights of the people across from them on the battlefield — that's the position you'd be putting them into if you had them enforce the law in American cities," he said.
Re-Examining Military Doctrine
The notion of amending the act first surfaced last month, when Sen. John Warner, R-Va., wrote the secretary of defense asking his department to "re-examine military doctrines," including Posse, to "enable our active duty military to more fully join other domestic assets in the war against terrorism."
Deputy Secretary of Defense Paul Wolfowitz, testifying before the Armed Services committee, said he "strongly agrees" with Warner on the issue. As of now, however, there is little more than talk on the issue.
"Certainly the Department of Defense is looking at all the ways to defeat terrorism and provide homeland security for our nation — but I'm not aware of any single situation right now where we are in a need of pursuing an exception to the Posse Comitatus Act," said Lt. Col. Dan Stoneking, a Defense Department spokesman. "I haven't heard of any concrete recommendation for any changes."
Besides, experts say, the Posse act as it stands does not preclude the U.S. from using soldiers to patrol nuclear facilities, enforce quarantines in the event of another bio-attack or even to restore domestic order, whatever that takes.
In fact, the military is already on the case. The Marines recently formed three counter-terrorism units charged with deterring, detecting and defending against terrorist activity on domestic soil.
Under normal circumstances, such moves might not be necessary, says Paul Schott Stevens, an attorney and former legal adviser to the National Security Council for President Ronald Reagan. “But we are facing circumstances that aren't normal," he says. "If we had a bio-attack tomorrow in the United States it might be necessary to impose and enforce quarantines. It isn't something that anyone predicted would happen, but the DOD needs to be thinking about expanding its role."
J. Kelly McCann, a Marine and special operations expert who runs his own training facility out of Virginia, says there is a role for the military in homeland defense, but perhaps not in law enforcement.
"That would be a mistake. No one wants big numbers of domestic military patrols," he said. The Military should be there to augment law enforcement and only when it is clearly out of the authority of local, state and federal enforcement agencies, he said.
Others argue that new times call for new attitudes about law enforcement.
"Before, homeland security was viewed as a law enforcement issue and a criminal justice matter," Stevens offered. "Now it isn't simply a crime, but an act of war against the U.S. and if that is the case, the (Department of Defense) must of course be involved."