This latest alarming claim could turn out likewise. But no one can take that risk. Better to get it wrong - for all the chaos that the announcement has brought to British airports and massive damage to the airline industry - than to have what would be an even larger act of mass murder than the bomb attacks in London 13 months ago. In cases like this, there is nothing the government can do but err on the side of caution. Imagine the response if something horrible was to happen and the government had not taken the most careful measures to protect the flying public at large when given advanced warning. 

The announcements most certainly brought chaos to British airports on a scale not seen since 9/11 with all domestic UK flights and many foreign flights canceled, foreign airlines canceling their own flights to the country and no guarantee that things would be back to normal by today. No government, certainly not one responsible for the busiest airport in the world, is going to allow that to happen without good reason - and the possibility of mass murder is a very good reason. There is much more at stake than canceled flights and the economic impact of interrupted air travel. 

The revelation of such a plot is going to hit the UK hard. It is bound to have major economic consequences - for the airline industry only now getting over the devastating downturn after 9/11; for the British tourist industry worth billions; and for London, one of the world's major business capitals. 

We do not yet know if this is Al-Qaeda at work, although it has in the past threatened to blow up British and American trans-Atlantic flights. The problem in accusing Al-Qaeda of involvement in any terror attacks is that there are many Al-Qaeda wannabes out there, dreaming of glory and self-righteously plotting their own little independent jihads against the West.