New Delhi, July 2 -- BRUSSELS - At the French entry point near Lyon, a departure gate closed Thursday before a Swiss family of four could board a Rome-bound flight they had arrived for ninety minutes early. They had cleared customs. What stopped them was a five-hour queue at the biometric scanner.

Multiplied across airports from Amsterdam to Vienna, scenes like this are now the norm, not the exception. Four of Europe's largest aviation and tourism industry groups warned Thursday that the EU's new digital border system has pushed conditions to a "critical point" ahead of the summer peak, putting 41 million tourist arrivals and $45.4 billion in visitor spending at risk.

The system in question is the Entry/Exit System, or EES. It records f...