September 2017, on the tarmac of Papa Air base in Hungary, U.S.-led paratroopers were simulating an airborne operation aimed at repelling an enemy force occupying a NATO ally territory. During the exercises, Hodges, commanding general of the United States Army Europe, was informed that his helicopter would have to divert from its intended route in order to clear customs in Romania. Such passport and customs checks constitute typical routine in Europe since military personnel and equipment are still subject to physical, legal and regulatory barriers.  ose obstacles could lead to delays, which even if they are not hugely time-consuming, represent a bureaucratic burden that poses a risk to military speed and proficiency…