Securing stables after horses have scarpered is an accusation those responsible for aviation security constantly face. After each scare - from 9/11 and the shoe bomber to the "soft drinks" threat and Glasgow airport's car bomb attack - steps are taken to stop the terrorist deploying that tactic again.
Sometimes these steps become farcical: first-class passengers eat in-flight delicacies with plastic, old ladies remove shoes for X-ray at security, while water and toothpaste tubes are confiscated from harassed parents. The latest move has been to ban cars from dropping off passengers outside many terminals.
With crowded airports struggling, the effect has been to make the experience of embarking on an aircraft journey less and less tolerable. Although, as the queues of shuffling misery prove, it has not stopped us flying, the public's stoicism cannot be taken for granted forever.
The challenge is to make sure we stay on our guard to the next possible attack, without allowing these "sledgehammer" measures to become institutionalised long after the perceived specific threat has vanished.
It is vital those charged with ensuring our safety keep a step ahead of the enterprising would-be mass-killer, making sure deterrents and safeguards are in place.
But they must be just as prepared to remove security measures that are no longer relevant as to introduce new ones when a threat emerges.
Source: Flight International