Why doesn't Europe impose airline-level security on its trains?

From an American perspective, it may be surprising that the European train system by and large does not require passengers or luggage to go through metal detectors or identity checks prior to travel. And after last Friday, when an armed man suspected of being a terrorist was subdued on an Amsterdam-to-Paris Thalys train, slapping down a cross-border system of security and identity checks could seem an easy fix.

But such new security could pose a fundamental challenge to the concept of the European Union itself. And even if it could be done legally, it would still be extraordinarily expensive – and might just shift the danger elsewhere within Europe's many potential targets of terrorism.

Freedom of movement has been central to the creation of the European project since the Schengen agreement was signed in 1985 to get rid of internal border controls. The Schengen area now includes 22 EU member countries, as well as Iceland, Liechtenstein, Norway, and Switzerland.

Yves Pascouau, director of migration and mobility policies at the European Policy Center in Brussels, says that Europe has reached a new level of interdependency and integration between people and businesses, thanks to the Schengen agreement. While checking passports could help root out potential terrorists, and perhaps curb the growing number of illegal immigrants trying to pass through Europe’s borders, it would also recreate the passport system that the Schengen agreement specifically prohibits.

“It would mean that the level of liberty we’ve attained in Europe is too high and that we must go backwards,” says Mr. Pascouau. “This would also mean going backwards on the roots of European history, which have always been about gaining more freedom.”

Expensive reforms

Moreover, the cost of reintroducing border checks and dismantling the Schengen area could also send Europe’s finance ministers scrambling. While no one has thrown out official numbers of how much such a production would cost, Pascouau says it would be extreme.

“You’d have to reestablish border controls, hire people, buy equipment, secure the premises,” says Pascouau. “Also from an economic point of view, this would be extremely costly. Transporting all the products that are carried mainly by road through the European Union would be longer and more expensive for companies and citizens.”

Even a more modest security upgrade could still prove prohibitively expensive. Guillaume Pepy, the president of France’s national railway SNCF, told French television Monday that installing gates at train entrances would require 20 times the investment made for airplanes and airports.

Leaders from Belgium, France, Germany, and the Netherlands have agreed to more modest measures, including an increase in patrols on trains and at international stations, and more baggage checks.

Chasing the problem

In addition, when it comes to attempting to stop criminals from carrying out attacks across borders, Europe faces the same struggle as any nation under threat: reinforcing one system inevitably takes the focus off of others, leaving them vulnerable to attack.

“The more you reinforce security in one area or one type of transport, the more risk there will be in another spot,” says Marc Hecker, a security and defense researcher at Paris’s IFRI think tank. “For example, the more you up security on the Thalys or the SNCF, the more criminals are going to look towards suburban trains or the metro.”

This opportunistic strategy has seen terrorists linked to ISIS, Boko Haram, or Al Qaeda in the Arabian Peninsula focus their attacks less on the ultra-secure airport system and more on unlikely places like churches, supermarkets, the beach, and schools.

Some see a cautionary tale in one response to illegal immigration, where it has been shown time and again that when one border goes up, another border will be penetrated.

As Hungary scrambles to finish a highly controversial 109-mile fence on its border with Serbia, many people from Syria and Afghanistan recently told the New York Times that news of the fence had only motivated them to move faster north. And in France, illegal immigrants are increasingly moving away from Calais’s increased security and towards nearby Dunkirk in their attempts to cross into Britain.