The Trump administration says the new rules were introduced because of intelligence that shows terrorists are continuing to target airlines flying to the United States. The Trump administration says the new rules were introduced because of intelligence that shows terrorists are continuing to target airlines flying to the US. Credit:AP An unidentified person familiar with the issue has told The Washington Post that officials have long been worried by a Syrian terrorist group that is trying to build bombs inside electronic devices that are hard to detect. However, as Demitri Sevastopulo and Robert Wright at the Financial Times suggest, non-US observers are skeptical of this explanation. They note that the United States has not been forthcoming about whether the ban is based on recent intelligence or long-standing concerns. There is also no explanation for why electronic devices in the cabin are a concern, and electronic devices in the baggage hold are not.

There is another explanation It may not be about security after all. Three of the airlines that have been targeted for these measures - Emirates, Etihad Airways and Qatar Airways - have long been accused by their US competitors of receiving massive effective subsidies from their governments. Government-subsidised Middle Eastern airlines such as Etihad Airways have feared for months there may be retaliation from the Trump administration. Is this it? Credit:AP These airlines have been quietly worried for months that President Trump was going to retaliate. This may be the retaliation. These three airlines, as well as the other airlines targeted in the order, are likely to lose a major amount of business from their most lucrative customers - people who travel in business class and first class.

Business travellers are disproportionately likely to want to work on the plane - the reason they are prepared to pay business-class or first-class fares is because it allows them to work in comfort. These travellers are unlikely to appreciate having to do all their work on smartphones, or not being able to work at all. The likely result is that many of them will stop flying on Gulf airlines, and start travelling on US airlines instead. As the Financial Times notes, the order doesn't affect only the airlines' direct flights to and from the United States - it attacks the "hub" airports that are at the core of their business models. These airlines not only fly passengers directly from the Gulf region to the United States - they also fly passengers from many other destinations, transferring them from one plane to another in the hubs. This "hub and spoke" approach is a standard economic model for long-haul airlines, offering them large savings. However, it also creates big vulnerabilities. If competitors or unfriendly states can undermine or degrade the hub, they can inflict heavy economic damage.

Weaponising interdependence As we have argued in the past, and talk about in forthcoming work, the US move can be understood as a variant form of "weaponised interdependence." We live in an interdependent world, where global networks span across countries, creating enormous benefits, but also great disparities of power. As networks grow, they tend to concentrate both influence and vulnerability in a few key locations, creating enormous opportunities for states, regulators and non-state actors who have leverage over those locations. In this context, the United States is plausibly leveraging its control over access to US airports, which are central "nodes" in the global network of air travel between different destinations.

It is using this control to attack the key vulnerabilities of other networked actors, by going after the central nodes in their networks (the hub airports) and potentially severely damaging them. What can Gulf airline carriers do? Gulf airlines have tried to defend themselves against political attacks from US competitors by appealing to free trade principles. The problem is that standard free trade agreements, such as World Trade Organisation rules, don't really apply to airlines (although they do apply to related sectors, such as the manufacture of airplanes). This has allowed the Gulf airlines to enjoy massive subsidies, without having to worry too much about being sued in the WTO. However, it also makes it hard for Gulf states or the states of other affected airlines to take a WTO case against the new US rules, even if these rules turn out to be motivated by protectionism and the desire to retaliate, rather than real underlying security questions.

If this were happening in a different sector, it would make for a pretty interesting case. States preserve carve-outs from international trade rules when they feel that their security is at stake. Would the United States prevail in a case like this, where there is a colourable security justification, but where there is also a very plausible argument that the real motivation doesn't have much to do with security? Or would the WTO defer to the United States' proposed justification? It's very likely that the Trump administration will make more unilateral rules that are justified using the language of national security, but are plausibly motivated by protectionism, so we may find out.

Loading Farrell is associate professor of political science and international affairs at George Washington University. Newman is associate professor of international politics at Georgetown University. For other commentary from The Monkey Cage, an independent blog anchored by a group of political scientists from universities around the country, see www.washingtonpost.com/blogs/monkey-cage. The Washington Post