Britain joined the U.S. in creating new restrictions for passengers traveling on flights from airports in several Muslim-majority countries. Here's what you need to know. (Monica Akhtar,Dani Player/The Washington Post)

Citing unspecified threats, the U.S. government told a slew of airlines based in the Middle East and North Africa that they must restrict their U.S.-bound passengers from taking any electronic items larger than cellphones in their carry-on baggage, effective immediately. The new rules affect 10 airports across the region, many of which serve as busy gateways for global business and tourism traffic. Britain followed suit, but its rules were significantly different though based on the "same intelligence the U.S. relies on."

U.S. government officials speaking on the condition of anonymity said the decision reflected “evaluated intelligence.” Security analysts have indeed long been aware that terrorist groups such as al-Qaeda and Somalia-based al-Shabab are experimenting with turning laptops and other electronic devices into bombs. As Washington Post transportation write Lori Aratani noted, “One example cited involved a bomb, possibly hidden in a laptop, that exploded on board a Somali plane going from Mogadishu to Djibouti, not a U.S.-bound flight.”

But there are two caveats: U.S.-bound passengers will still be able to travel with the restricted electronics, but they will have to keep the devices in their checked baggage. And U.S.-based airlines, if they were to fly to the affected airports, would not be subject to the restrictions.

These loopholes have led many analysts and journalists to question the logic underpinning the new rules:

If a laptop can be converted into a bomb, what difference does it make if you check it or carry it onboard? Does that imply that the screening process for checked baggage is more stringent than for carry-ons? Haven't most in-air bombing incidents been caused by explosives in the cargo holds of planes?

And what exactly stops a prospective bomber from boarding a flight in any other unaffected airport? What makes Middle East and North Africa-based airlines — many considered world-class — more susceptible? With heavy security measures already in place in many Middle Eastern airports, how do the new rules add extra vigilance?

With answers to these questions conspicuously absent, other theories have arisen about the impetus for the new rules. One centers on the administration's professed protectionist instincts regarding U.S. businesses.

In February, President Trump met with executives of U.S. airlines and pledged that he would help them compete against foreign carriers that receive subsidies from their home governments. In terms of international traffic, airlines such as Emirates, Etihad, Turkish Airlines and Qatar Airways — all affected by the new restrictions — are U.S. carriers' biggest competitors.

“A lot of that competition is subsidized by governments, big league,” Trump said at that meeting. “I’ve heard that complaint from different people in this room. Probably about one hour after I got elected, I was inundated with calls from your industry and many other industries, because it’s a very unfair situation.”

For business travelers flying long-haul via major transit hubs serviced by these airlines, the inability to carry, say, a work laptop onboard would be a crippling disadvantage. Inevitably, these travelers, as well as some leisure travelers, would choose to fly on unaffected (and largely U.S.- or Europe-based) airlines instead.

Several journalists and activists expressed shock at the rules, noting that they would have to part ways with personal and possibly sensitive data stored on their devices.

Because the affected airports are such busy transit hubs, the new rules are expected to have a reverberating effect on global travel. More than 83 million passengers traveled through Dubai's airport in 2016, and gateways in Doha, Qatar and Istanbul are some of the busiest in the world. Airlines — particularly those based in rich, Persian Gulf states — have taken advantage of their geographic centrality and serve as the main waypoint between the Western and Eastern hemispheres.

Correction: A previous version of this article implied that United Airlines currently flies to Dubai. It does not.