WASHINGTON - Flashes in the skies over Baghdad yesterday seemed too remote and surreal to shake many Americans out of their usual routines. But, for some, the opening of the war with Iraq brought out raw emotions and high anxieties.

"It's terrifying, honestly," said Angel Borgstrom, owner of the Squash Blossom Market and Deli in Daphne, Ala. "I have an ominous feeling, waiting to see what the retaliation is going to be and whether or not it will be on American soil."

Nervous that the war with Iraq might prompt retaliatory terrorist strikes in the United States, Borgstrom urged her mother yesterday morning to cut short a road trip and head to the safety of home.

In her health-food store in Daphne, a small town on the Alabama coast, Borgstrom has almost sold out her $12 boxes of potassium iodide, marketed as anti-radiation pills in the event of a nuclear attack.

"Fear of retaliation," she said, "is the undercurrent today."

As the Bush administration argues that Iraq has aided terrorists and possesses weapons of mass destruction, polls show a majority of Americans favor the war. Though the administration failed to secure United Nations approval for the U.S.-led invasion - amid opposition from such countries as France, Germany and Russia - these Americans say they believe that the attack on Iraq will make the world safer.

"It takes a real gutsy person to step into a war - I happen to think President Bush is a great leader," said John Chandler, owner of a car dealership in Amarillo, Texas. "I was glad to see it started. Everybody's been kind of on pins and needles about when it's going to happen, so getting it started is a relief in a lot of ways."

As the Pentagon withheld a full-scale onslaught against Iraq yesterday, some predicted that the war would end quickly.

"I'm very comfortable knowing we have the technology - it's almost like they have pop guns compared to us," said Larry Mitchell, 58, a barber in the small southern Oklahoma town of Ardmore. "I feel like [Hussein's] people are going to surrender like crazy."

For others, the start of war brought uncertainty and jitters.

With the nation's terrorist alert at "orange," the second-highest level, police were out in force at potential targets such as bridges and historic landmarks. In major cities, office workers girded themselves for the unexpected.

At the American Association of Health Plans, a trade association based in downtown Washington, the building's approximately 130 workers studied pictures posted in staff kitchens showing steps to take in the event of a terrorist attack. Supplies of water and energy bars were stockpiled in the building - enough to sustain workers for a week.

Employees were briefed on evacuation routes, as well as "safe rooms" that have been established inside the three-story building. Emergency first-aid classes for staff are to begin as early as next week.

Even as the war got under way, some Americans said they felt uninformed about how much risk Iraq posed. For weeks, Lynda Fitzgerald has been waiting for proof of whether the war is absolutely necessary. She said she feels she lacks the evidence she needs.

"One side is saying, 'Yes, Iraq has these weapons, but you're going to have to take our word for it,' and the other side is saying, 'No, they don't have these weapons, but you're going to have to take our word for it,'" said Fitzgerald, 34, a Chicago bookstore employee. "I feel like I don't know what's going on well enough, and it's frustrating."

Some said they worried that regardless of the threat Iraq poses, the fact that the United States attacked without United Nations backing makes Americans even more susceptible to terrorism.

In West Hartford, Conn., Dianne Rechel, a real estate agent, said she has abandoned thoughts of a possible summer vacation in Vancouver, figuring that the wartime climate would make it unsafe to travel even to that quiet Canadian city.

The tension is getting to her son, too, she said. The 11-year-old boy recently started having nightmares about things catching on fire, something Rechel said she believes is related to the fearful times.

Yesterday, Rechel prepared signs for a war protest and planned to attend church services. Beyond her family's safety, she said, she is worried about citizens in Iraq.

"All I hear is noise on TV and see bright lights - but for Iraqis, those sounds are right over their heads, human beings are running for cover, mothers are herding their children into basements or bunkers in order to survive," she said. "I'm trying to put myself in their shoes, and it's almost impossible. I can't fathom it."

But others, even as they expressed concerns about the safety of Iraqis and the unknown global consequences of this conflict, called war the only option.

At EJ's Luncheonette, a chain of New York City diners that is taking Gruyere cheese off its menu to tweak the French for opposing the war, support for Bush is strong.

"Being a New Yorker and experiencing Sept. 11 and knowing that these Iraqis are capable of harboring terrorists and harming the world - we've got to address the situation now, before it gets any worse," said Steve Elkins, who manages the EJ's on the Upper West Side.

"The United States has a duty to protect the world."