There are multiple reasons why, as far as that can be determined, making such an operation challenging at best.

First of, this secret operation would have been an Abwehr operation. However, the Abwehr was a comparatively ineffective service, if compared to the western services and never develoloped a reach far enough into the Soviet territory. Also, it was in a rivalry with the Sicherheitsdienst (SD) of the SS.

Additionally, the Stalinist regime and the NKVD had a rather firm grip on the country, both ideologically and in terms of control, making any coup/revolt very challenging.

Also, such an uprising would need an existing resistance in the country, that could be helped to rise up. Due to the large distances, lacking coordination of possible revolters and the oppressive regime, this was not the case.

Furthermore it is questionable whether the Reich would have been able to equip and supply such a revolt, considering the lack of production capacity and the necessary air superiority to support and supply a revolt by air.

There are however, at least two attempts that broadly move in this direction. One is the (failed) attempt to assassinate Stalin as part of Unternehmen Zeppelin. The other is the buildup of the Russian National Liberation Army (29. Waffen-Grenadier-Division der SS „RONA“ (russische Nr. 1)), that incorporated anti-communist Russians and other Soviet ethnicities.

Hey there,

Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.

If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!