Two years ago a bolt of terrorism lifted the United States off its underpinnings and dropped it facing a new direction.
It's true that today most Americans don't feel personally endangered in the aftermath of Sept. 11. A relative few have stockpiled duct tape and plastic sheeting. Remembrances of the worst attacks ever on the continental US are fewer and more muted than last year. Time has rewritten shock and grief into elegy.
But the physical effects of the attacks can be seen in every air terminal and port in the country. The budget of the new Department of Homeland Security is $38 billion, and rising. Terrorism and the US response have introduced a powerful new narrative into the national culture. There is - obviously - a big difference now in how the US government conducts itself in the world.
For many, the most profound change may be a lingering feeling that something yet more may occur, somewhere within US boundaries. The blows of Sept. 11 perhaps pierced Americans' bubble of denial - or innocence - about their relative isolation from the furies of the world.
"We can't fool ourselves any longer that we're not vulnerable," says Charles Figley, a Florida State University social work professor who is studying the effects of the terrorist attacks.
Last year, the first anniversary of the terrorist attacks on the World Trade Center and Pentagon provided the US an opportunity to stop and mourn events that were still vivid in memory. President Bush, for instance, traveled with first lady Laura Bush to both sites, plus the field in Shanksville, Pennsylvania, where a hijacked jetliner crashed after passengers attempted to regain control.
This year, plans called for Bush to attend memorial services but stay in Washington, closer to home. The more subdued schedule reflected a number of concerns, among them the continued fighting in Iraq.
The generally lower-key observances in the US this year do not reflect a judgment that the attacks weren't as pivotal as they seemed at the time. To the contrary, a just-released Ipsos US Express poll found that the number of Americans who believe Sept. 11 changed the world forever has actually increased in the past 12 months, from 74 to 82 percent.
But a growing sense of import does not necessarily translate into personal concern. A year of national alerts jumping from yellow to orange and back again, and vague warnings about a possible strike, possibly somewhere, has generally affected those who live in Washington or other obvious target areas the most.
A new Christian Science Monitor/TIPP poll finds that 78 percent of respondents feel at least somewhat safe from a terrorist act on US soil. For all the publicity about worried Americans jamming Home Depot, few have followed government suggestions for physical preparation. Seventy-six percent have taken no steps, such as setting aside food, to protect themselves or their families.
It isn't that Americans are willfully ignoring obvious danger. A plurality of 40 percent judges that they are more at risk from terrorists than they were a year ago. It seems more that those in the US have an idea of what might and might not be a target - and a certain fatalism about the next move of shadowy forces.
Take Luis Perez, a student from Pembroke Pines, Fla. Mr. Perez can't help but remember Sept. 11 - it's his birthday. The former New Yorker was 19 when the World Trade Center fell.
"If terrorists decide to attack, then they will decide to attack," he says, nonchalantly. "There's nothing we can do about it."
Of course, that's not the attitude they're taking at the new Department of Homeland Security. Headquartered at an historic military installation in northwest Washington, Secretary Tom Ridge and his 170,000 employees are making a start on making the nation safer.
The department has begun the mammoth task of consolidating the nation's three border inspection agencies into one. It's trying to make it easier for state and local governments to get antiterrorism aid and grants.
Mr. Ridge has also vowed to provide 5,000 more armed federal law-enforcement officials to ensure air safety even as investigations have shown it's still possible to sneak onto many runways via baggage belts.
At airports, longer lines and increased screening are just the most visible alterations in daily life due to the attacks.
"Most of our added security isn't visible to the naked eye," says Monique Bond, spokeswoman for the Chicago Department of Aviation, which oversees O'Hare and Midway airports.
Skyscraper management has changed as well. The collapse of the twin towers has ensured that no one will ever look at tall buildings quite the same way. At Chicago's 110-story Sears Tower security used to be an afterthought. Now it's in the forefront, with added metal detectors, identification cards to allow floor access, and physical barriers around the building's base.
"Cars that are parking in the building's lot underneath are searched and looked at - you have to open the trunk," says a financial services firm manager who works on the 85th floor.
To some extent the events of Sept. 11, 2001, have already become one of the nation's defining stories about itself. Like Pearl Harbor, it is a narrative of surprise, defeat, and arousal. Unlike Pearl Harbor it is a narrative not yet ended by known victory.
Immediately after the attacks there was a surge of interest in producing television dramas about the US and its war on terrorism, says Victoria Rifkin, president of the Writer's Guild of America, West. But that surge has abated. As the war on terror has veered into Iraq and elsewhere, reality has become uncinematic.
"It's more difficult to deal with what's going on right now - perhaps too difficult to portray in a script," says Ms. Rifkin.
• Anne Stein in Chicago, Chris Richard in Los Angeles, and Jennifer LeClaire in Miami contributed to this report.