WASHINGTON – They are always there, at the president’s side or nearby, hiding in plain sight.

At any given time, five people hold the title of White House military aide, a not particularly revealing description for the men and women who take turns carrying “the football,” the leather briefcase stocked with the classified nuclear war plan.

It is a plum assignment and a burnout job, in the estimation of those who have done it.

But do not ask those who carry the football for President Bush; they are not allowed to talk about it.

“You’re always kind of on edge,” recalled Robert Patterson, who carried the football for President Clinton as an Air Force major and then lieutenant colonel. “I opened it up constantly just to refresh myself, to always be aware of what was in it, all the potential decisions the president could possibly make.”

Bob Barrett, who carried the football 20 years earlier for President Ford as an Army major, still vividly recalls the job’s benefits and burdens: an intimate, close-up view of the presidency and the awesome responsibility of being constantly prepared to assist the president in the event of a nuclear attack.

“You’re wonderfully overwhelmed by it,” said Mr. Barrett, who became so close to Mr. Ford that he left the military and served on Mr. Ford’s staff when the president left office.

Mr. Barrett also remembers the palpitations he felt during a trip to France when the football inadvertently was left behind at the airport as Mr. Barrett departed in a motorcade with Mr. Ford. Before long, an American security official passed the suitcase through the window to him from a moving car that caught up to the motorcade.

The football is more properly known as the president’s emergency satchel. It got its nickname because an early version of the nuclear war plan – the SIOP, or Single Integrated Operational Plan – was code-named “dropkick.”

The small black bag first appeared, without public announcement, during the Kennedy administration in the aftermath of the Cuban missile crisis, when the government saw a need for the president to have nuclear decision-making tools at the ready, even when away from the White House.

Now, long after the end of the Cold War, the lethal luggage still shadows the president. The war plans still are updated regularly. Those who carry the satchel still are trained to help the president prepare for a nuclear attack in mere minutes.

Some question whether that is still necessary; others believe it is needed now more than ever.

Specifics of the football’s contents are classified. It is known to contain a handbook detailing options for unleashing American nuclear weapons – “everything from firing a tactical nuclear weapon, one of them, to full-born Armageddon,” Mr. Patterson said.

The plans were so complex that Jimmy Carter, the only president to really study them closely, ordered that a simplified summary be included, the president of the private Center for Defense Information and a former Minuteman launch officer, Bruce Blair, said. Mr. Blair said one source described the summary to him as “virtually a cartoon version.”

Mr. Patterson equates it to “a Denny’s breakfast menu.”

“It’s kind of like picking one out of Column A and two out of Column B,” he said.

There is speculation the briefcase was opened during the attacks of September 11, 2001, because it contains information about maintaining the continuity of government and about communication and evacuation procedures during a national emergency.

“There was a continuity of government plan that was put into effect, and the documents that lay out what the president should do would be found in the suitcase,” Mr. Blair said.

Rules for handling the football are classified and probably have changed over the years. Former White House aides recall strict guidelines for keeping it close to the president.

It should always be on the same elevator with him, for example, and always on the same helicopter. Some aides kept it in hand while jogging with the president. Mr. Patterson said he would stow the reinforced briefcase, which he estimated weighs 45 pounds, in one of the secure vehicles that shadowed Mr. Clinton on his runs.

“It’s not difficult to carry around,” says Rep. John Kline, a Republican of Minnesota, who carried the football for Mr. Carter and President Reagan as a Marine. “You can put it down, and I did often.”

When the president is at the White House, the football is kept in a secure location. One of the military aides always is able to retrieve it quickly.

There also is a spare football at the White House, and a third satchel that remains close to the vice president.