"The source went on to point out that human intelligence ( infiltrating one of your own men into the target organisation) could mean months or years living in a third world country as one of them.

Few people can be persuaded that Dysentry as a way of life might be a good career to follow.

Nevertheless the source stated that the "Afghan" desk pre 9/11 comprised a handful of people... none of whom would stay on that desk more then a year or two, and that if one or two of them could actually speak Afghan, that was a bonus. "

That sounds extremely inaccurate.

The point being that most of our best intelligence comes from foreign sources sympathetic to American and Western interests, or willing to help the West to promote their own agendas ( especially if the price is right)

Our best Afghan agents are Afghans, and our best CIA analysts are probably naturalized Americans who immigrated from Afghanistan years earlier. I imagine it's exactly the same case for the UK.

A great example of this is what happened after Sep. 11 here in the US. When it became apparent that the perpetrators were Islamic terrorists under Osama Bin Laden's Al Queda organization, the phones at the FBI starting ringing off the hook. By phone calls from shocked, angry, scared, outraged Arab-Americans, Pakistani-Americans, Africans, and Asians who gave the FBI quite literally tens of thousands of tips on nasty people they knew, or knew of, back in their homelands, who were sympathetic to Al Queda and its goals. That's an enormous database of invaluable intelligence, which has undoubtedly prevented some terrorist attacks already. And it's far more than we could have ever gotten "on our own".