1) demoralize the people of a country over a period of "at least 15 to 20 years;"
2) destabilize the country's institutions over a period of "2 to 5 years;"
3) precipitate a crisis that would normally unfold over a period of "up to 6 weeks;" and
4) normalize the new state of affairs.
Whether the KGB and its successor organization(s) could have or might have been successful is of course debatable, but no one can deny this kind of persistent effort to subvert another country's people over such a long horizon is... audacious (words fail me).
In particular, I find the idea of a long-term government-sponsored program whose goal is to "demoralize" people a bit upsetting: It stands directly against the let's-roll-up-our-sleeves, we-can-do-it optimism for which US entrepreneurs have long been known around the world.