On Thursday, we learned that Mohammed Siddique Khan made a video explaining why he bombed the London subway system on July 7 -- and including some nice words about al Qaeda's leadership.

Some excerpts from the BBC analysis piece:

There are several indications of the al-Qaeda connection.

Firstly, the Arabic TV channel al-Jazeera, which received the tape, attributes it to "the al-Qaeda organisation."

Khan spoke English on the video shown on al-Jazeera news channel

Second, the fact that Khan's statement is accompanied on the tape by one from Zawahri. This strongly supports the view that Khan must have made contact with al-Qaeda elements, probably when he was in Pakistan from November last year to February this year.

It is possible, even probable, that Khan made the tape in Pakistan and came back to the UK determined on his course.

Third, Khan refers on the tape to the al-Qaeda leadership when he talks about "today's heroes beloved Sheikh Osama Bin Laden, Dr Ayman al-Zawahri and Abu Musab al-Zarqawi". Zarqawi is the leader of the al-Qaeda faction in Iraq.

Fourth, the language he uses is that of the dedicated al-Qaeda fighter. He calls himself a soldier and speaks about his religious and political motives. His religious motive is seen in a passage that ends: "I ask you to make du'a [a supplication] to Allah Almighty to accept the work from me and my brothers and enter us into gardens of paradise."

'Scholars of beggary'

His political motive is explained thus: "Your democratically elected governments continuously perpetuate atrocities against my people all over the world."

Zawahri criticised Britain's Muslim leaders

The issue of whether Iraq was his motivation is not entirely cleared up. It certainly appears to be part of it. His statement also speaks about "the bombing, gassing, imprisonment and torture of my people."

His motivation probably includes Iraq but is not confined to it. Khan defines his people as Muslims, so regards attacks on them anywhere as a justification.

Zawahri does make the connection. He states: "The lands and interests of the countries that took part in the aggression against Palestine, Iraq, and Afghanistan are targets for us."

What remains interesting is that there was no electronic "chatter" before the July 7 attack, which could mean al Qaeda has either learned to mask its communications better or that there simply is no need to do so: They have found self-sufficient domestic cells to work with.

While the BBC analysis says Ayman al-Zawahiri didn't take direct responsibility for the first London attack, it doesn't mention that al Qaeda (until I'm very wrong) has never taken direct responsibility for 9/11 either.