When terrorist bombs exploded in Brussels Tuesday, something like panic came over Joi Gibbs. After all, the Norcross woman had planned to be standing in Brussels tomorrow.

All week she struggled with her fear. Her first impulse was to cancel her whirlwind, weeklong train trip through Europe. By Friday, she scratched Brussels off the list.

Seth Zimmerman of Sandy Springs thought Paris and Amsterdam sounded like romantic places for a 15th wedding anniversary trip. Now, having heard that Belgian officials missed clear warnings on one of the bombers, he has doubts about security across Europe and is rethinking the trip.

“It just feels like they don’t have a handle on what’s going on,” he said.

Travel worries may be the clearest sign of how the unrest in Europe — terror attacks as well as the migrant crisis — is registering here in the U.S. But the fears stoked by these events are also intensifying American political debate on border security, immigration reform and the treatment of Muslims in this country.

Analysts say the attacks have opened many Americans’ eyes to the terror problems in Europe. Unfortunately, they see much of the reaction expressed in fears.

“Paris was shaken in such a violent manner that it really shook things up in a new way,” said Judith A. Miller, an Emory University history professor who specializes in French history. “Brussels gets amalgamated with that.”

She added, “Now people are saying if it can happen in Paris and Brussels, it could happen anywhere in Europe.”

II. ‘Known for chocolate and beer’

Coming on the heels of the Paris attacks, the explosions in the Brussels subway and airport created a wave of sympathy from Americans. But even as Americans pull closer emotionally to the people of Europe, they are becoming less likely to want to visit there, analysts say.

That worries people in metro Atlanta who have close ties to that part of the world, and who fear that American attitudes are changing.

“Belgium is a very hospitality-oriented country. Lots of my friends work in the hospitality industry,” said Frederik Cambie, 40, who was born there but now lives in East Atlanta Village. “As a country, we are known for chocolate and beer. We don’t want to be known for terrorism.”

Cambie joined about 50 other people Thursday at a vigil for the Brussels bombings, which killed at least 31 and injured 300. He wore the red, yellow and black colors of his country on a hat, pins and a scarf. But he acknowledged that the mood was much like that of a funeral.

Cambie came to Atlanta for the Olympic games in 1996, and he said the Brussels attacks rekindled memories of when he was only blocks away from the bombing of Centennial Olympic Park.

Patrick Van Biesen, who also donned his country’s colors for the vigil, said even he thought twice about flying home for a July wedding.

“My first reaction was maybe not go,” he said. “But I don’t want to give the terrorists the pleasure.”

The Paris terror attack was a “game changer” in terms of Americans’ perception of terrorism in Europe, analysts said. The November attack, which killed 130 and injured 368, was hardly the start of Islamic terrorism in Europe, but Americans’ strong emotional connection to that city prompted genuine grief and sustained support.

Since the Paris attack, interest in travel to Europe has waned, said Patrick Surry, chief data scientist for Hopper, the airfare prediction app. Hopper analyzes Internet searches on travel websites.

The Brussels attack created an even larger drop in interest, he said. People may have thought the Paris attack was a one-time event, but the Brussels bombings create the perception of an ominous pattern. The targets of an airport and city subway add to the wariness.

Worse, the news this week has focused on criticism of security measures in Brussels and Europe, enhancing people’s sense of unease. The U.S. State Department issued a broad warning on travel in Europe, saying, “Terrorist groups continue to plan near-term attacks throughout Europe, targeting sporting events, tourist sites, restaurants and transportation.”

To date, Internet searches for European trips have dropped about 13 percent on Hopper compared to a year ago, said Surry, who expects that figure to grow.

“It’s not getting people into the mindset of a relaxing European vacation,” Surry said. “It’s making people look at other plans to travel.”

Pamela Kilgore-Smith, owner of 4Luv2Travel in McDonough, said she’s had several clients put off trips to European destinations because of safety concerns.

It’s been largely just European travel, she said. Clients with trips to the Caribbean still plan to go.

“As long as it’s in the news and in the forefront, people will pay attention,” Kilgore-Smith said.

III. Playing into the terrorists’ hands

Political analysts say they see a steamrolling effect from all the bad news out of Europe.

Many people link the terror strikes with the stream of Syrian refugees that has spilled across Europe. These issues have also fueled the debate in America on border security, immigration reform and the treatment of Muslims, said Anthony Lemieux, an associate professor of communications at Georgia State University.

But Lemieux, who studies terrorist motivations, said the harsher rhetoric in this presidential election — the talk of walling off borders and patrolling Muslim neighborhoods in the U.S. — plays into the hands of Islamic State terrorists.

He said the terrorists want to foster an atmosphere of clear opposition between Muslims and other groups, thereby eliminating the “gray zone” of trust and cooperation between them.

But Robin Simcox, who works on counter-terrorism issues at the Heritage Foundation, said it’s important to have a robust discussion of the threats facing the U.S., even if they include contentious ideas.

He said some countries have suffered because they failed to have a full discussion on the integration of new groups and the recognition of the effects of radicalization.

“Those kinds of discussions need to be out there,” he said.

IV. ‘Changing my whole mindset’

Joi Gibbs planned to depart Saturday for London, Amsterdam and Paris. She said she’s keeping a close eye on the news, and just about everything else.

The decision to skip Brussels did not come easily. She weighed the possibilities again and again.

Is it safe to go right now?

Would the terrorists strike again so soon?

She even dreamed of confronting a terrorist in a convenience store and calling out “Bomb!” before throwing her stuff down and fleeing.

A single bit of news tipped her mental scale. On Friday, explosions and gunfire occurred during police raids in Brussels, which resulted in the arrest of three terror suspects.

“That sealed it,” she said.

But her nervousness has not subsided.

When she’s at the Eiffel Tower, she’s going to be scanning the crowd. At Buckingham palace, she’s going to snap pictures and get away from the crowds there. She’s worried about riding the trains.

“This attack is changing my whole trip, my whole mindset,” Gibbs said. “I’m not going to be able to relax.”