Every day, it seems, there is a new fallout from the war on terror; sometimes it is young soldiers dying in Afghanistan, or maybe political destabilisation in Pakistan, or, as on Christmas Day, another bomb plot to blow an aircraft out of the sky. And in the wake of each new threat comes new restrictions on personal freedom.

Those of us of a certain age in Northern Ireland have experienced such restrictions during the three decades of our bitter sectarian conflict. We also know what it is like to be viewed with suspicion at airports and to have to undergo rigorous checks, even before air piracy or bombing of flights became a reality.

After 9/11 restrictions on flights became commonplace throughout the world with bans on bottles of liquid above a certain size and more stringent searches at terminals. However, experience shows that determined terrorists will find some way of breaching security, and in the wake of the latest threat security is likely to be ramped up again. That will mean longer waits at terminals, more thorough baggage and body searches, and tougher restrictions on what can be carried in aircraft cabins.

The Israelis, who have lived under constant threat, successfully use passenger profiling to foil would-be bombers on their national airline and this practice may well be extended to other carriers. While it is never entirely comfortable to accede to greater and greater restrictions on personal freedom, a balance has to be found between civil liberties and safety in the air. Ultimately passengers will put up with tougher security, possibly even the use of body scanners, if it means reaching their destination safely. Such is the wanton nature of modern terrorism, we have no other choice.