After strangers joined in spontaneous celebrations, lit fireworks, uncorked champagne and sang the national anthem — after midnight elation finally gave way to morning reflection — Americans awoke Monday to a more nuanced realization.

The first day without Osama bin Laden was not so different from the 3,520 that preceded it.

There was still fear, still grief, still war. There was still the incessant threat of terrorism at home and abroad, prompting the latest official warning for travelers about “anti-American sentiment.” There were still security checkpoints and full body scanners, three-volley salutes and workers digging graves at Arlington National Cemetery.

Even after bin Laden’s death, America continued to live in the world he helped create.

The reaction unfolded in two distinct parts. The first came Sunday night, when thousands gathered at Ground Zero and outside the White House to wave American flags and chant “U-S-A! U-S-A!” Hundreds of public officials released statements about “revenge,” “victory,” “relief” and “closure.” At a time when the country desperately craved something to shout about — with two wars, a faltering economy, an escalating debt and a historic partisan divide — here was something unequivocally great: A precise military action. An enemy killed. A testament to American resiliency.

But endings usually do not come so clean, and on Monday the country began to draw conclusions more personal and complex. A public official groused: Why had it taken so long to find bin Laden? A mother in Portland, Ore., explained to her daughter: “There are more bad guys out there.” A woman in the security line at the Denver airport wondered: How could she ever be truly safe?

“I don’t think we’re going to be safe, period,” said Gail Meagher, a retiree from Syracuse, N.Y., who was visiting grandchildren in Denver. “But, finally, something has been accomplished. We’ve made a statement.”

But, she added: “We’re not safe from these people. They hate us.”

At Arlington, a family picnicked at the grave of a 25-year-old relative who died while trying to rid the world of terror. All around them were stark reminders that his mission remained unfinished, even after bin Laden’s death. Planes flew low overhead, turning sharply toward Reagan National Airport to avoid the no-fly zone over the Capitol. A horse-drawn caisson delivered another soldier to his grave. A bugler again sounded taps.

“It’s just the world we live in right now,” said Kristen Forse, 29, as she and her two daughters rearranged the photos, note cards, carnations and pebbles at the Section 60 tombstone of her brother, David James Smith, a Marine sergeant killed in Afghanistan. “There’s always been a fight against good and evil, and today is just a battle won for the good.”

A few rows away, workers were packing the dirt atop another serviceman. At 11 a.m., the body of Sgt. Sean T. Callahan, a Marine killed in Afghanistan, was lowered into Grave 9515. Across the grassy field, over the whistles of oak trees and hum of idling tour buses, a uniformed Navy contingent was rehearsing in crisp precision for yet another interment.

“We shouldn’t have to see this seven or eight times a day,” said Will Sajeski, 32, as he watched nearby from his grandfather’s grave. “We don’t have control over anything anymore. We’ve lost control over here because of everything that goes on over there.”

Other people across the country expressed the same sense of powerlessness and inevitability: Even though bin Laden helped start a cycle of war and terror, his death will do little to end it, they said.

“They might try to amp up the attacks,” said Randall Holcomb, the doorman at B.B. King’s Blues Club in Memphis. “It’s bad to say this, but bin Laden kind of created the terror environment. He’s gone now, but there’s going to be someone else right in his position, probably right now.”

“Now all of his people are going to retaliate,” agreed David Moore, a doorman at a bar down the street. “This could happen all over.”

In Tuscaloosa, Ala., where people are still suffering from last week’s devastating tornadoes, Lorinda Rodriguez-Mitchell took a brief break from one disaster to think about another. She had traveled 90 miles from her home town to help with the rescue effort in Tuscaloosa — just as she had 10 years ago when she went to New York to counsel victims of the Sept. 11 attacks. She had only learned about bin Laden’s death Monday morning, because there wasn’t a working television within miles. Even once she heard the news, she hardly paused to celebrate.

“It’s great, great, great,” she said before turning her focus again to the crisis in Alabama, where there is a tattered American flag flying from a nearby utility pole at the center point of destruction that people had begun referring to as Ground Zero. This was the reality of Rodriguez-Mitchell’s life: Sept. 11 had been one disaster. Here again was another. Soon there would be more.

On a college campus in Richmond, students who were just entering grade school on Sept. 11, 2001, took a break from their classes Monday and discussed how terrorism and disaster had come to define the modern era.

“All we have ever known is the restrictions he has put on us,” said Caitlyn Maze, 18, a student at Virginia Commonwealth University.

“Our generation has never known a time without him,” said Morganne Carroll, 19.

A day after the country killed its top terrorist target, it continued to focus on preventing another attack. At New York’s John F. Kennedy International Airport, a woman stood barefoot on a dirty floor after removing her shoes for security reasons. “Gotta remember to wear socks,” the TSA agent told her.

It was a normal day at the airport — normal, anyway, by the standards of the post-Sept. 11 world. Show your driver’s license. Hand over the boarding pass. Take off your shoes. Remove your jacket. Place your laptop in a separate plastic bin.

“Ten years ago, you just put your bag down and went through,” said Devin Evers, 22. He was catching a flight home to Burnsville, Minn. The television screens in the airport flashed breaking news: “Bin Laden Dead!” But in Monday’s security line — and in so many other ways — his legacy endured.

Staff writers Rosalind S. Helderman in New York, Anita Kumar in Virginia, Jerry Markon in Tennessee, Ed O’Keefe in Alabama and Barbara Vobejda in Colorado contributed to this report.