It's a matter of opinion when the Germans sealed their fate. Starting the War with Russia, the Dash for Stalingrad, whatever! The fact remains that you can argue that they lost the war ANYWHERE. I like to believe that the war was lost back in 1919, when Ebb (or something starting with 'E', i forget his name) failed to tell his comrade (who's name i've also forgotten) that he wanted Germany to be reformed back into a Monarchy, and his comrade announced that Germany was to become a Republic; begetting the Weimar, begetting NSDAP, begetting Hitler becoming Chancellor, begetting...well, you get the picture...
...anyhoo, i've found a way to kill the Hades in no time flat - screw Silent Threat! Play FS2!!...