And a senior intel official says that this is a "conservative estimate:"

The would-be killers are among 2,000 extremists who the security services have said are based in Britain and actively planning terrorist activity of some kind.

The figures are contained within a secret government report on the "enduring terrorist threat" facing the UK from al-Qaeda and affiliated organisations, The Sunday Telegraph has been told.

While the deaths of Osama bin Laden and Anwar al-Awlaki may have left al-Qaeda without a charismatic leader, both the Secret Intelligence Service, MI6, and the Security Service, MI5, believe the organisation remains as dangerous as ever.

The warning comes as Britain begins preparations for next year's 2012 Olympic Games, which has been described by MI5 as the biggest security operation in the country's history.

So, where are they? Why hasn't America been inundated with Muslim terrorists who detonate suicide bombs at malls, in theaters, or sporting events?

We've gotten extremely lucky in stopping the few terrorist cells that have set up shop here since 9/11. We'ved also interdicted some home grown terror plots.

But outside of the lone wolf attacks of a Major Nidal and others, why haven't we suffered from a rash of single-terrorist suicide attacks, which is the preferred method of dealing out death just about everywhere else in the world?

Truck bombs, car bombs, suicide vests - one would think that we would have been hit at least once since 9/11. The reason is that we are winning the war against the terrorists. We are smashing their infrastructure, denying them funds, interferring with their travel, getting wind of their plots in advance, arresting or killing their leaders. And we are doing it with the help of our friends, allies, and even our enemies who share a common security concern about terrorism.

This state of affairs is not likely to continue forever. As Dick Cheney pointed out long ago, the government must succeed 100% of the time while the terrorists need only be succcessful once.

With those odds, and despite our huge successes in fighting terrorism and the networks that use it, we will likely be hit eventually.