From Heathrow in London to Dubai International to Charles De Gaulle in Paris, there is a new intense focus on electronic devices at international airports.
U.S.-bound passengers must now turn their devices on before departure to prove they're not hollowed out and packed with explosives, U.S. officials announced this weekend.
Phones, laptops, tablets, cameras, e-readers, music players and game consoles are all subject to be checked if a passenger is randomly selected for the new screening.
And as inconvenient as the new rules will likely be for the flying public, experts say the threat is real.
"The danger with electronic devices is the ability to hide something metal, like a military or commercial detonator, which makes a bomb extremely reliable," former ATF Special Agent in Charge Jim Cavanaugh told NBC News.
"I think it's absolutely just a matter of time until al Qaeda and associated groups attempt another aviation attack using concealed IEDs (improvised explosive devices)," said Michael Leiter, a former director of the National Counterterrorism Center under Presidents Bush and Obama and an NBC News analyst. "Whether or not it's a matter of time until they're successful is really another question."
U.S. officials first put out a notice that the Department of Homeland Security was asking for "enhanced security measures" at foreign airports last week — without the details about the electronic devices — based on new intelligence that extremists fighting in Syria and Iraq are teaming up with a notorious al Qaeda bombmaker.
That person, Ibrahim Hassan al-Asiri, is suspected of being the top bombmaker for al Qaeda in the Arabian Peninsula. The 32-year-old Saudi is based in Yemen and believed to have supplied the infamous "underwear bomb" that failed to detonate on a Christmas flight in 2009.
According to terrorism experts, some of AQAP's leadership have recently praised their fellow Sunni militants in the Islamic State of Iraq and al-Sham, also known as ISIS, which is rampaging across Syria and northern Iraq, and it's conceivable that the two groups would be working closely together to attack foreign targets.
The TSA will not disclose which airports will be conducting the additional screening and electronic device requirements — industry data shows that more than 250 foreign airports offer nonstop service to the U.S.
During an interview aired Sunday on NBC's "Meet The Press," Homeland Security Secretary Jeh Johnson refused to speculate on whether the new security procedures called for overseas would soon be required at domestic airports.
"We continue to evaluate things," he said. "In this instance we felt that it was important to crank it up some at the last point of departure airports and we'll continually evaluate the situation."
Heathrow, Europe's busiest airport, told passengers that they might not be allowed to take electronic devices onto planes if they could not be switched on. It posted a security update on its website telling passengers, "If you are flying to the US please make sure any of your electronic devices are charged before you travel."
And on Monday, British Airways also issued an update for passengers flying from Britain to the U.S.
"Customers may be asked to turn on any electronic or battery powered devices such as telephones, tablets, e-books and laptops in front of security teams and/or demonstrate the item's functionality," the update said.
"If, when asked to do so, you are unable to demonstrate that your device has power you will not be allowed to fly on your planned service."
Kate Hanni, with the passenger advocacy group Flyer's Rights, said she was "encouraged that they are taking these steps and I do not think it’s just another inconvenience." She noted, however, that bomb-sniffing dogs are one of the best defenses against explosives.
It's unclear how many passengers will be selected for the new screenings, but travelers in Europe headed to America could be facing big delays — with the beefed up restrictions potentially turning airports into centers of mass confusion and frustration.