So now the search begins. It’s difficult to imagine how the police and intelligence services will go about tracking down the people who committed yesterday’s mayhem when all the clues have been subjected to ferocious bomb blasting but we can be sure they’ll go all out to do just that.

Unbelievably it seems that traces of explosive have already been found at more than one of the crime scenes. An in-depth study of all available CCTV footage will take place in the hope of obtaining visual clues to the identities of the bombers.

The use of forensic clues in the piecing together of what can be a complex puzzle has yielded the police positive results in the past. The Oklahoma bomb was made of ammonium nitrate and the bomber, Timothy McVeigh, was linked to the explosion when forensics discovered his fingerprints on a receipt for the purchase of one ton of the chemical.

And, from the BBC:

In the aftermath of the Omagh bombing, which killed 29 people, 35 tonnes of rubble was collected and two complete telephone boxes, from which the warning calls were made, were wrapped in polythene and lifted by helicopter to a laboratory. A man is now awaiting trial.

The search for a reason for this act can be almost as bewildering as the search for clues in the rubble. My best guess is that this was an act of bravado – look, we can get you whenever we feel like it – and spite, a simple desire to lash out and inflict enormous pain on an enemy one detests. In a perverse way, these people – unlike most of their co-religionists – believe slaughter and carnage actually enhances their religion and proves its potency.

And it’s part of an ongoing conflict between violent Islam and the West. The idea that Iraq is the cause is too simplistic. As The Telegraph points out, this attack is one of a long line of attacks starting in 1993 when the World Trade Centre in New York experienced its first bomb attack. There then followed attacks in Saudi Arabia (1995 and 1996), the American Embassies in Nairobi and Dar-es-Salaam in 1998 and then the 2000 attack on the destroyer USS Cole, which killed 17 sailors. Bali was bombed in October 2002 – five months before the Iraq invasion.

And, as we know, the targets for these terrorists aren’t just the west or westerners. From The Times:

AL-QAEDA’S organisation in Iraq said yesterday that it had killed Egypt’s Ambassador-designate, five days after kidnapping him in Baghdad.

Quite where we go form here is unknown. Much will be said but, I believe, the power of decision is not with us. The ability to act lies with the terrorists; the will to act is proven. We can prepare at best but I don’t think we can prevent.