According to apologists for the Nazi regime, Stalin, despite retreating from the more immediate expansionist ambitions of the Soviet regime in the post-WW1 chaos period, was intending to ultimately invade Europe after industrialization in the USSR prepared it for war. (I'm given to understand that there's also a school of thought associated with the book Icebreaker by a Soviet defector arguing that Stalin intended to attack in 1941.) And, thus, the German invasion of Russia and Russian-occupied territory in Eastern Europe was supposedly a just pre-emptive war of self-defense. Is this accurate?
Let me emphasize that I'm not looking for an answer that only focuses on the other, ideological, motivations of the Nazi regime in terms of drang nach osten settler colonialism and imperialism. Nor am I looking for a catalog of war crimes committed by German and German-allied forces in what Synder terms the "Bloodlands" during the war. I'm quite interested in both these topics, and if there's something really interesting/relevant from them you want to mention in your response, please do; but what I'm really trying to learn more about here is the long-term strategic thinking of the German and Russian regimes before the outbreak of the war.
Looking at Soviet military planning, the military was in no shape to invade anything in 1941. Consider this: the three new tanks that were just adopted into service (T-34, KV-1, T-40) had no manual written for them when the war broke out, nor were the manuals scheduled to be written until late 1941. Production of the T-34 and KV tanks were a trickle, completely inadequate to completely replace the army's ageing BT-7s until 1943. The T-34 was also going to be replaced by the T-34M in production in late 1941, the T-26 replaced with the T-50, and the KV-1 replaced with the KV-3 in the short term and then thorough trials of the KV-4 and KV-5 in 1942 would determine what the Red Army's heavy tank would be in the future. Artillery would also change (Kulik pushed the development of 85 mm divisional artillery and powerful 107 mm anti-tank guns). The Winter War proved the need for a high velocity 152 mm gun or 203 mm howitzer in a mobile chassis, but no such SPG was ready in 1941.
The problems with the Red Army weren't only of a technical nature. Rapid expansion resulted in a lack of junior officers and NCOs. It would take years before the ranks of the army were sufficiently filled up again.
In short, the Red Army was in the middle of a modernization and expansion program. It was in absolutely no shape to be attacking anyone in 1941 or most likely even in 1942.