The security restrictions being placed on Philadelphia for the papal visit invite comparison to the fenced-in "closed cities" of World War II.
Or Manhattan after the 9/11 terrorist attacks.
Or American cities patrolled by National Guard troops during riots in the 1960s.
Rarely has a peacetime event drawn such Draconian security measures across such a broad section of a U.S. city.
Overkill is the word being used by some law enforcement and transportation officials for the sweeping shutdown of highways and bridges, and the creation of a Beirut-style "green zone" where most vehicle traffic will be forbidden.
"It's like they're trying to hypnotize us: 'You will like this, you will like this,'" said one official, who requested anonymity.
"Every law enforcement agency in the region thinks they're relevant," said another. "Everybody's getting involved. It's crazy."
The officials, who attended planning meetings for papal security, were not authorized to discuss the plans on the record.
Chain-link fences to protect the pope and corral visitors are reminiscent of the fences that closed Oak Ridge, Tenn., and Los Alamos, N.M., during World War II, when those cities were shut to outsiders because of the secret work of scientists on the Manhattan Project to build the first atomic bombs.
Other American cities have been closed because of riots and civil unrest, notably in the 1960s, when National Guard soldiers enforced curfews and set up barricades.
More recently, many Americans have vivid memories of Manhattan immediately after the 9/11 attacks, with bridges and highways closed to all but emergency workers.
But in peacetime, cities have hosted political conventions, Olympics, inaugurations, and sports celebrations without the kind of security net being draped over Philadelphia.
They have even hosted popes without this kind of security.
In October 1979, Pope John Paul II drew about 1.2 million spectators for his appearances in Philadelphia, with throngs for his motorcade from Philadelphia International Airport up Broad Street and 400,000 in Logan Square for a Mass.
There were no special SEPTA passes required to get to Center City, no green zones, and no fences to keep out the unsecure.
The pope slipped his minders several times to mingle with children and others in the crowd, although Philadelphia police and Secret Service agents were always close at hand.
"The only noticeable discontent was at Logan Circle, where a number of holders of rare silver tickets were denied their seats, apparently because of the presence of hundreds of counterfeit tickets," the Philadelphia Daily News reported at the time. "Despite that headache, an estimated 400,000 jammed the circle and surrounding streets for the Mass."
But things have changed since 1979.
Especially since 9/11, security has trumped convenience, comfort, and ease of movement. Concern about violence lurks at every mass gathering, especially when prominent leaders are present.
"Better safe than sorry" has become the unofficial motto of the nation.
So the Secret Service has directed many of the decisions made by local law enforcement and transportation officials for the papal visit, prompting some officials to complain privately of "heavy-handed" tactics by the feds.