The fight against terror

The US's response to the attacks remains uncertain

By the BBC's Legal Affairs Correspondent Jon Silverman

The promise by chancellor Gordon Brown to look again at the way terrorist organisations are funded throws the spotlight on the life-support system without which Osama Bin Laden's network would struggle to survive.

And this is where the City of London's role as one of the world's main financial arteries is important.

Money laundering not only sustains drug trafficking and organised crime but also terrorism.

Mr Brown has promised to make laundered money harder to move.

Mr Brown has vowed to go after terrorist money

And he noted that one bank account had already been closed down this week.

The names of suspicious clients have also been circulated to banks.

Legislation to tackle the problem already exists in the form of the 2000 Terrorism Act.

That gave the police strengthened powers to strike at terrorist funding and seek forfeiture of assets.

There are three forms of low-level criminality that support terrorist organisations.

They are credit-card theft, bank fraud and identity theft - assuming someone's identity in the form of stolen documents and siphoning off their funds.

There is evidence that Bin Laden's organisation, al Quaida, engages in all three.

We have got to make it absolutely plain that we are prepared to deliver not just messages of solidarity but real, practical co-operation

EU Commissioner, Chris Patten

It also has the advantage of being truly multi-national with dedicated followers in the US, Britain and a number of countries on the European continent - especially France, Belgium and Italy.

The fact that it operates across national boundaries explains the impetus for a European Union wide response to the terror attacks in the US.

EU Commissioner, Chris Patten, said collaboration was vital.

"We have got to make it absolutely plain that we are prepared to deliver not just messages of solidarity but real, practical co-operation," he said.

But law enforcement and the intelligence agencies face a dilemma.

Many of the Bin Laden supporters in the UK are not terrorists in the sense of planting bombs.

Bin Laden's organisation is believed to engage in fraud

They do provide logistical support.

But they are compartmentalised into small cells.

And invariably, their recruits are young Muslims with no criminal record.

They can be monitored by surveillance.

But penetration by agents has proved extremely difficult.

Despite the horrendous nature of the attacks in the US - and the uncertainty surrounding a military response - the assessment by the security authorities is that Britain is not currently at heightened risk of a terrorist attack.

But that view may have to be radically revised if there is a major strike on Bin Laden's host state, Afghanistan.