The letters KUOS stand for "Advanced Officer Perfectioning Course" (КУОС: Курсы Усовершенствования Офицерского Состава). Under that rather banal name stood an absolutely unique KGB organization: the KUOS was tasked with creating special forces operators which would also be real, fully trained spies and real, fully trained special operators. I know, many countries and organizations (including the US CIA) claim to have such forces, but in reality only the Soviets succeeded in creating such a very rare breed of agents.
In September of 1991 I had the very rare opportunity to personally meet several KUOS graduates one evening in Moscow, in a very private and informal setting (in fact, we spend much of the night drinking, singing songs and talking about the past when we used to be mortal enemies of each other) and one of them, a former Kaskad commander, became a good friend of mine. I am absolutely sure that all of these men would much rather die than to commit an act of treason. No, Poteev must have been a "walk-in".
To make things even worse, Poteevs' father was a Hero of the Soviet Union, a WWII veteran of the tank forces (he died in 1972).
Most KUOS officers left during the early Eltsin years, many drowned their disgust and pain in alcohol, other left to live in faraway rural villages. Some made a brilliant career in the new Russian "business" world. Some, very few, even stayed in, or close to, the various current FSB Spetsnaz units and schools. But all in all, the old KGB Spetsnaz are a thing of the past, never to be re-created again.