it was Hitler's order to Guderian and Rommel to stop the German armored units before Dunkirk, which gave the British Expeditionary Force enough time to get to safety across the English Channel
the German generals were furious as they saw a unique opportunity to inflict a decisive defeat on the British and French
Hitler, on the other hand, wanted to enter into an alliance with Great Britain, a serious mistake that decisively changed the course of the war
and yes, it was the Red Army that won the war against Germany, not the USA