The military aspect centered on the 500 km strip of land between the border and the Dnieper-Dvina river line. This was the maximum logistical range achieved with the innovation of intermediate supply dumps. Any further advance would require a delay to refit. All strength would be concentrated at the border to rapidly annihilate the Red Army before the river line in a series of encirclement maneuvers. It was then expected that the Bolshevik regime would begin to crumble and offer little resistance in operations on the Baltic and Ukraine followed by a march on Moscow.
With the information available there were reasons to doubt both the economic value that could be extracted from the territory aswell as the possibility of its conquest itself.
Von Bock, commander of Army Group Center, was seriously worried about the possibility of the Red Army escaping beyond the Dnieper-Dvina line. The Soviet Union’s size, population, poor infrastructure and ongoing industrialization were well known; on the other hand, there was still a large developmental gap which made it not unreasonable to assume the Red Army was weak. And if the regime faced political disintegration, it would suffer from poor infrastructure as much as the invaders.
One of the earliest war games and Generalmajor Marcks, who drafted the first plan, predicted that, if the destruction of the Red Army and capture of Moscow didn’t happen quickly, Germany would be locked in a long and grim two-front war. Marcks saw a relief in that control of the Baltic and the Ukraine would facilitate survival in this long war.
And yet the Wehrmacht’s military-economic office and the Four Year Plan’s staff showed the Ukraine’s grain surplus was modest. Hauling it west would require fuel for a large fleet of trucks, and yet an early military-geographic study ruled out an immediate takeover of Caucasian oil fields. Franz Halder of the OKH’s General Staff believed an invasion wouldn’t significantly improve Germany’s resource base.

Despite all of this the generals could not oppose Barbarossa. There was rejection from the Foreign Ministry, but after the success of summer 1940 Hitler was in too strong of a position to be veered off course. Although flawed, the decision to invade the USSR had a rational basis. It was not just a way to survive a war of attrition in the West but also seemed to be a strike on the “weakest link in the chain”. Only on land Germany had supremacy; it seemed easier to employ the battle-proven Heer against an apparently weak enemy than bash the Kriegsmarine and Luftwaffe against strong defenses.
Besides this pragmatic/economic logic, there were the ideological reasons, such as defeating Bolshevism and securing living space. Those motivations complemented each other: if, on one hand, Germany had to conquer the East quickly so it could survive the Anglo-American coalition, on the other hand it also had to fulfill its ideological objectives quickly before the strength of the West fell over it.