This wasn't anyting like "unexpected" and it wasn't German but German and Soviet invasion. --Taw
Viktor Suworow , (book Ice-Breaker) and book "Der Tag M" (M=Mobilizing Day) proved that the Soviet Army under Stalin was ready to attack. Suworow recently inspected many documents. He was trained in Soviet Army at Suworow Officer School in Kaliningrad and at Officer College Kiev.
Further down in the article it needs to be stated , that the main reason, for bogging down the German army, was weather, the rains and early winter . H. Jonat
I think it needs to be pointed out that the Germans were bogged down by the weather at Moscow mainly because they first took a detour southward earlier in the campaign. Hitler ordered Army Group Center southward to conquer the Ukraine in a pincer operation instead of taking Moscow earlier in the campaign. I believe that several of Hitler's generals, including Guderian, argued against this. By the time they returned towards the push to Moscow, the muds and then the snows had stopped the advance. -- Egern