FOR ALL THE time jihadi groups spend fantasising about ways to commit mass murder, there is a pretty conventional terrorist mind-set behind most of the plots that materialise.

The security services anticipate all manner of possible terror attacks on Britain — chemical, biological, radiological, and cyber attacks, and cunning assaults on key infrastructure. There is a great deal of loose chat among would-be jihadis about such exotic homicidal possibilities. Kamel Bourgass, the Wood Green “ricin plotter”, intended to smear deadly poison on strap handles in the Tube and on door knobs in London’s Jewish neighbourhoods. But he failed to make any effective ricin. If wishes were horses, jihadis would ride a very long way.

It is still aircraft and explosives that loom large in the jihadi imagination. There is nothing quite so photogenic as a stricken aircraft, or quite so obscenely violent as a mid-air explosion. Salman Rushdie’s The Satanic Verses begins with this very image. Jihadis are drawn to the images of Dawson’s Field in Jordan during September 1970 when four hijacked airliners were blown up by the Popular Front for the Liberation of Palestine. The memory of Lockerbie still sticks in the mind. Khalid Sheikh Mohammad, the chief operational planner of al-Qaeda until his arrest in 2002, lavished attention on a plan in 1995 to blow up maybe ten US airliners over the Pacific. Al-Qaeda terrorists tried to bring down an El Al airliner taking off from Mombasa in 2002 with two Stinger missiles, and to this day it’s a wonder that they missed.

Commercial aircraft represent globalism and high technology — they shrink the world and threaten cultural conservatism. The Boeing 747 was the last of the “great machines” that characterised the 20th century: it opened up air travel to the mass market. And it was so very American; big, brash and useful. But aircraft also appear vulnerable. In truth, civil aircraft are a lot more robust than people think, but the aviation industry is selling safety almost as much as it is selling transport and passengers need constant reassurance that aircraft are operating well within their technical limits.

So destroying or hijacking aircraft has always had great symbolic value for terrorists. Since the first commercial aircraft was hijacked in 1948 — a Cathay Pacific seaplane out of Macau — there have been almost 40 significant airline hijacks. Most ended with little or no loss of life, hence the presumption among crew and passengers that it was as well to go along with a hijack if you were unfortunate enough to get caught in one. There were manuals on how to relate to hijackers, or to avoid being singled out by them; it was a routine that hijackers and airlines both came to know.

All that changed with the 9/11 atrocities. If a plane is hijacked by jihadis intent on crashing it, then simple arithmetic would come into play: there are six of them and 200 of you. Like the passengers on United 93, there is nothing to lose by resistance. Hijacking in the traditional sense is out of fashion. But destroying aircraft is not. Richard Reid, the would-be shoe bomber, was caught making a comically inept, though dangerous, attempt to blow a hole in the side of an aircraft just three months after 9/11. American Intelligence reported a plot to board aircraft in Eastern Europe where security is lax, take them over and crash them into Heathrow during their final approach. It is not clear that this plot got beyond the talking stage, though British jihadi chatter has recently speculated on the prospects of getting “thirty brothers” on board a single aircraft, to control it long enough to destroy it.

The plot revealed yesterday may have been intended to run along similar lines: to get a number of terrorists each with small amounts of explosives on board multiple aircraft bound for the US. Explosives could then be pooled in-flight and detonated to make a catastrophic hole in the aircraft’s skin or blast a way on to a locked flight deck. Such a manoeuvre is not as easy as it sounds and again the simple arithmetic would apply once the terrorists began to act suspiciously. But the symbolic prize for the jihadis of destroying yet more aircraft after 9/11, of indiscriminate British and American deaths, hitting the air bridge across the Atlantic and of panicking the aviation industry into major disruption must remain tempting.

Facing the terrorist who thinks like this, British airports, more than most others in the world, are caught between the drive for significant extra security and the impetus to keep the world’s busiest transit hub moving. El Al, the Israeli airline, deals with passengers who accept much tougher security than we would be willing to tolerate, and the airline takes calculated risks with armed sky marshals on flights in anticipation of a mid-air struggle. But El Al’s levels of security are not practical for the rest of us except in the short term. In the immediate future there will doubtless be great disruption at our airports and possibly the installation of expensive monitoring equipment.

Airlines, however, will continue to be attractive targets for terrorists and the vulnerability and glamour of any machine travelling at 600mph at 30,000ft, will not diminish, whatever measures are taken at airports. The most effective way to deal with terrorism is still intelligence-led policing, and if yesterday’s operation is as significant as the security services indicate, they will have struck a good old-fashioned blow against a bad new fashionable terror technique.

Michael Clarke is Professor of Defence Studies at King’s College London

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