The next terrorist attacks on civilian aircraft could be carried out by passengers who hide their bomb ingredients in innocent-looking containers for talcum powder, baby formula or medicine bottles and assemble their weapon behind a locked restroom door, security experts warn.
The announcement Thursday of a foiled terror plot aiming to blow up flights from London to the United States using explosives hidden in hand luggage pointed to a potential new chapter in the battle against airline terrorism: a world of hours-long security checks, visual inspections of prescription drugs, and bans on bringing liquids or laptops on board.
Several bomb-disposal experts and troubleshooters for airline security interviewed by The Associated Press said mobile phones, computers, wrist watches or anything else with a battery should be prohibited from flights.
Perhaps most chillingly, they warn that security staff at airports are not looking for the right things anymore - and the change in tactics required is likely to overwhelm current security standards.
"That theater we see, of people taking off shoes, is not going to stop a suicide bomber. The terrorists have already sniffed out the weak spots and are adopting new tactics," said Irish security analyst Tom Clonan, who noted that security measures usually adapt to the last attack, not the next threat.
He said that a terrorist group will almost certainly try to blow up a plane with a bomb assembled on board unless security measures improved fundamentally.
Anti-terrorist authorities in Britain and the United States declined to describe the bomb design used by terrorists in the foiled plot - whether they were primarily liquid or, more likely, contained liquids in a more complex ingredient list.
Whatever the case, experts predicted passengers may soon have to change their travel habits radically.
"Every businessman needs to have his laptop on a long-haul flight, and now you won't be able to. Even a battery-operated watch would provide enough power for a detonator. All you need is one shock," said Alan Hatcher, managing director of the International School for Security and Explosives Education in Salisbury, England.
Airlines have toyed with the idea of banning innocuous personal-care items from carry-on luggage following previous security scares, only to have the focus switch elsewhere because of the mammoth difficulty of enforcing tougher rules. Thursday's announcement dramatically raises the likelihood that security will come first no matter what the logistical hurdles.
The technology for the kind of liquid or crystallized explosives possibly involved in the thwarted terror plot is not new.
The threat first appeared in January 1995 in the Philippines, when police stumbled upon a suspected al-Qaida plot to target U.S.-bound, long-haul planes with bombs based on nitroglycerine carried on board in containers for contact-lens solution.
At that time, aviation authorities announced plans to ban aerosols, bottled gels and containers of liquids holding more than 30 milliliters on U.S. airliners departing Manila, an idea never properly enforced.
Even then, baby formula was excluded from the limits - even though, in its powdered form, it could provide a good vehicle for masking crystallized explosives.
A decade later in Belfast, Northern Ireland, an Algerian man was convicted of possessing 25 computer disk drives detailing how to bring down an aircraft using, among other things, crystallized explosives hidden in a container of talcum powder.
During that trial an FBI explosives expert, Donald Sachtleben, testified he had built and successfully detonated three bombs based on the instructions found in the Algerian's home.
Despite this decade-old knowledge, security officials in Dublin and across Europe still permit passengers to carry on a wide range of receptacles without any visual inspection.