At this point in the war, Germany could not replace its losses. Here's What You Need To Remember: The Nazis failed spectacularly in the summer of 1944 for three main reasons - elaborated below. The Soviet army’s Operation Bagration offensive in June 1944 destroyed their greatest nemesis — Nazi Germany’s Army Group Center — and drove hundreds of thousands of Soviet troops and thousands of tanks from east of Minsk into the Third Reich itself. It was, arguably, the greatest disaster for Germany in World War II, ironically kicking off three years to the day after Germany’s invasion of the Soviet Union, and resulting in more than 400,000 casualties inflicted on the Reich’s already badly-depleted armed forces.