Why did this intelligence operation succeed so brilliantly?

A new history book by Bruce Reidel, ex-USG and now at Brookings, 'What We Won: America's Secret War in Afghanistan, 1979-1989' and he talks in a hour-long podcast:http://www.lawfareblog.com/2014/07/t...m-afghanistan/

Just started to listen and from the link:
In his talk, Riedel discusses why the American intelligence operation in Afghanistan in the 1980s was so successful, and what, if any lessons, the United States can apply to its ongoing operations in the country. Riedel also explored the complex personalities and individuals who shaped the war, and explained how their influence still affects the region today.
He credits General Zia ul-Haq with being the key player, he decided when Stinger should be deployed; supported by the USG, Saudi Arabia (official and private funding).

Buyers (USA):http://www.amazon.com/What-We-Won-Am...n%2C+1979-1989

UK buyers:http://www.amazon.co.uk/What-We-Won-...ion/B00JAN2UVK