A particular turning point?

Narrator's post:

Just as German and Japanese mistakes and failures in military strategy and economic production were crucial to overall Allied victory, so too was the Allied response to bridging and ultimately gaining the advantage in these areas. Individually, indeed doing so represented a turning point for the Allies. Collectively however, campaigns such as Barbarossa served as evidence of the combined impacts of these areas; the advantage gained in one area had either direct or indirect impacts upon the other areas in question. For instance, the recapturing of Soviet territory initially occupied by German forces meant therefore that Germany had less access to resources for production, increasing the chances of the Soviets and the Allies in gaining the advantage in overall economic production. Likewise, Japanese failure to improve the Zero against new planes such as the Hellcat by the US helped contribute not only to the US gaining the technological advantage over Japan in the Pacific, but more importantly, helped facilitate the US in gaining gradual command of the air as she pressed further with her “Island- Hopping” campaign in the Pacific. Just as command of the sky had proven to be crucial to Japanese, so was such command crucial to overall American strategy in this theater. Finally, as an example of Axis mistakes and failures and its impacts upon the military, political and moral areas, German failure to finish off the British army at Dunkirk or to defeat the RAF in the Battle of Britain was costly. These failures combined to give Churchill a renewed determination to fight on, and in conjunction rallied the British people to stand against perceived Nazi aggression. More importantly, German failure ensured Britain would become to launch point for Operation Overlord to liberate Europe in 1944. From hindsight, Hitler and Nazi Germany helped contribute to its own downfall.