Amin Shokrollahi couldn't wait to lecture at an electronics conference in San Francisco. The annual gathering of top tech minds, investors and customers was the perfect place for the German-Iranian professor to gain support for his start-up.
But before he could make his trip to the January forum, Shokrollahi discovered his permission to travel to the United States from Switzerland had been revoked. He immediately knew why. Just weeks before his flight, Congress had made changes to the visa waiver program, which allowed citizens of 38 countries to travel to the U.S. without a visa.
After the deadly terrorist attacks in Paris and San Bernardino, Congress amended the program so that those with dual citizenship in Iran, Iraq, Sudan and Syria, as well as people who have traveled to those countries in the last five years, had to apply for a visa. Last month, the Department of Homeland Security announced further restrictions for those who have recently traveled to Libya, Somalia and Yemen.
Shokrollahi, 52, ended up missing the conference, as well as meetings with potential investors. About a week later, the U.S. consulate granted him a yearlong visa. But the earlier episode, with its lost opportunities, rankled him.
"Most of the people being affected, the vast majority, they are being wrongfully targeted," said Shokrollahi, a mathematician who teaches at Swiss Federal Institute of Technology in Lausanne. "It's like giving broad spectrum antibiotics that kill everything because you want to kill a few bacteria."
Edwin Smith, an expert in international law at USC, said the decision Congress made balanced the freedom to travel with national security interests. Dual-national terrorists who are able to sneak into the country pose a real threat, he said.
"The thing that Daesh would like very much is to have dual-national Europeans get into the U.S.," Smith said, using the Arabic acronym for Islamic State. "That's the nightmare scenario."
But in recent weeks, Silicon Valley has been at the forefront of a push against the restrictions. The changes, tech leaders argued, would be bad for their bottom line if people doing business with their companies had difficulty coming to the U.S. And they worry that European countries will retaliate against U.S. travelers with similar restrictions.
In a letter to Congress, the leaders of dozens of companies, including Twitter, Dropbox and Pinterest, called the policy discriminatory.
"We protest this just as vigorously as if Congress had mandated special travel papers for citizens based on their faith or the color of their skin," the letter said. "In the balancing act between fighting terrorism and upholding American liberties, these provisions go too far."
Ali Partovi, a tech investor and Iranian émigré, compared the restrictions to new sanctions, just months after a landmark nuclear deal led the U.S. to ease long-standing sanctions against Iran.
"They're a sanction against Europe and against American companies that do business with Europe," Partovi, 43, said. "Any company that has offices in Europe, or sells products to European customers, or buys from European suppliers, is impacted."
The European Union is scheduled to review the issue in April and has suggested that the bloc may suspend visa-free travel to Europe for all Americans for a year. Should the European Commission retaliate, it would not be the first time the union has found itself in a tit-for-tat battle with the U.S.
The EU slapped its first tariffs on a wide range of U.S. agricultural and manufactured goods in 2004 in a retaliatory move intended to pressure Congress to make significant changes in the way U.S. corporations were taxed.
The State Department has declined to comment on the possibility that Americans could face visa restrictions in response to the law Congress passed.
"Look, I'm not going to speak to what Europe writ large may or may not do or individual governments may or may not do," State Department spokesman Mark C. Toner said at a January news briefing.
The 30-year-old visa waiver program, which grants 90-day stays, is credited with bolstering the U.S. tourism industry.
Hooman Radfar, a partner at the San Francisco start-up studio Expa, said the change to the visa waiver program could be particularly difficult for small businesses because "time is money."
"Not being able to have someone for a month, while that's maybe not a big deal for GE, for a small business it's catastrophic," Radfar said.
Radfar said his parents left Iran for the U.S. before he was born because they wanted the freedom they couldn't have in their native land. Allowing certain Europeans to be able to come to the U.S. with ease while making it harder for others is un-American, he said.
But the visa waiver bill that passed marked a relatively rare instance of bipartisan agreement in Washington.
California Sen. Dianne Feinstein, who introduced the Senate's version of the legislation, said new restrictions cut the risk of foreign fighters exploiting the visa program "by requiring individuals who have traveled to high-risk countries to use the traditional visa process." Feinstein's legislation prohibited visa-free travel for those who have traveled to Syria and Iraq. The dual-national provision originated in the House, officials said.
"I strongly believe that restricting use of the visa waiver program based on travel to high-risk countries will help prevent an estimated 5,000 foreign fighters from Europe who have trained in the Middle East from exploiting the program to enter the United States," Feinstein said in a statement.
But the senator said she disagreed with restrictions based on nationality, saying it "is discriminatory and not the correct path."
A month after the bill was passed, lawmakers in both chambers introduced bipartisan legislation that would eliminate the dual-national restrictions.
"I was disappointed the provision was included in legislation, over the strong objection of many members, and support the effort to repeal it," Feinstein said.
Partovi, the investor, said Iranians from all over the world work in the tech industry, and "have earned their way into Silicon Valley's top ranks.... When you do something that hurts Iranians, all of Silicon Valley feels it."
At Southern California college campuses, some Iranian students said they fear that European countries will impose the same restrictions on them that the U.S. is imposing on Iranians in other countries.
"We are alert, unified and ready to fight unjust discrimination like this," said UCLA student Arman Sharif, 19, who added that many Iranians in the U.S. have family in Europe. His mother's cousin lives in Germany.
Nikki Tavasoli, a graduate student of economics at UC Irvine, said she's concerned about the effect a reciprocal law would have on her career. A graduate student studying economics, Tavasoli said many of the conferences she's interested in attending take place in Europe. The 23-year-old, who has family in Sweden, said the move came "out of the blue."
"It's a blow to the Iranian diaspora," she said.
Her parents are upset by the law, Tavasoli added, but not as much as her. Like many older immigrant generations, "they don't want to ruffle any feathers," so they won't speak out, she said. Tavasoli, however, said she's willing to take a stand if Europe institutes similar laws.
"These are my rights," she said. "I am willing to fight for them."