In most Western education I've been taught that Hitler's invasion of the Soviet Union was a purely aggressive action and that Stalin was unprepared for war, and he was even caught off guard. However, I have begun to read more on the historiography and it appears that many Russian historians give credence to the idea that Stalin was planning to attack Hitler in 1941, and Hitler's invasion was mirrored by similar plans in the Stalin camp. I understand that the historical consensus leans more on the mainstream view, but how fringe is the other theory? Is it merely unorthodox, or outright wacky?
I've looked through several previous discussions, and I think this covers the information given in other answers: "How credible are the claims that the Soviets were actively planning to attack Nazi Germany, except the Germans struck first?" at https://www.reddit.com/r/AskHistorians/comments/3l7lba/how_credible_are_the_claims_that_the_soviets_were/cv41ms9/ (and two levels down), by /u/Georgy_K_Zhukov .
This is intended as a starting point, not to discourage further discussion. Follow-on questions, info, and debate are all welcome.