The current Cold War era Al Qaeda operatives are soldiers. They think like soldiers, they plan like soldiers, they organise themselves like soldiers would. The American response to Al Queda is the response as they would give to a marching army and column of tanks, a standard military response. So this war today is soldiers versus soldiers. And the Americans are considerably better soldiers, which is why they are making progress.
But the new generation of Al Qaeda, they are less like soldiers. They have the same determination, the same loyalty, the same anger and hatred, but they are not soldiers. They won't fight like soldiers, or think like soldiers, or organise themselves like soldiers. The Americans will still be soldiers, but Al Qaeda will not. They will be something quite different. They will organise themselves in such a way that they can most effectively and efficiently attack the US and its allies, in such a way that will make them considerably harder to discover, and they won't be tied down by the standard military practises of Osama bin Laden and his lot. While they learnt to fight through fighting back columns of Soviet troops, the new generation will start from day one with urban guerilla warfare in Iraq and how to maximise results from suicide attacks.
They will be 'terrorists' through and through.

I haven't (and not going to watch this) watch this because I don't have UK television.

Are the causes, even if they are somewhat fictionalised, for terrorists to perform the act seem believable?