The KGB along with the party and the Soviet Army were kind of the ironic counter part to the balance-of-powers system the US has. Each one had its strengths and weaknesses and they could keep an eye on each other. KGB was special because it had the information, the best educated people, it knew were resources were, how to get to them etc. When people talk about a conspiracy cabal that would control and pull strings behind the scenes, it was that cabal.
Because of the KGB was best positioned to take advantage of the power vacuum and many had turned to grab as many resources as possible after the fall of the Soviet Union. The most patriotic communists had turned super-capitalist practically overnight.
But at the same time, however, by late 80s and 90s few really believed in the "cause" so to speak. They probably all just wanted cushy jobs, fancy apartments and big pensions when they retired. And of course there were a lot of defections.
Even this group of spies from the story, remembering how many were making fun of their stupid and outdated methods, or praising the FBI for uncovering them, was ultimately betrayed by a defector. So was Hanssen.
Wondering if perhaps now SVR is in a better position today, as at least there is no need to pretend do believe in any great communist cause and then be disillusioned later, and defect. Perhaps now it is just business -- "You get a good job and if you betray us we'll find you and sprinkle some Polonium-210 in your tea".
https://www.amazon.com/Spy-Handler-Officer-Recruited-Hanssen...
It presents the story from the other side. It follows the carrier of the person who handled two highest profile defections to the Soviet Union: Hansen and Ames.
You can skip over some chapters of his childhood and early career. But has nice stories from Beirut (what used to be the Paris of the Middle East, also a popular playground for Spies), India, Australia and of course during his post as counter-intelligence chief in US.
It doesn't talk in depth about technical issues but more about handling of sources, procedures used, blackmailing tactics, honeypots.
Oh also talk about Robert Pelton's selling of Ivy Bells operation (probably a hundred million+ dollar cost) to the Russians for $35k. How they smuggled him out by shaving his beard and dressing him as a delivery worker.