What&#x27;s the point of declaring war on the basis of their promise to defend Poland, if they never actually did anything to help Poland?<p>It&#x27;s not nearly so simple as that. For example, the French had better tanks, as well as more tank. There were plusses and minuses on both sides, but the result is far from clear and certainly not an overwhelming advantage in either direction. Combine this with the German army being busy in Poland for several weeks, and the French and British had a great opportunity to start their part of the conflict on their own terms. Some highly-placed Germans stated after the war that they would have been totally screwed if the Allies had invaded then.<p>The Battle of France revealed that the Germans were capable of completely smashing the Allied forces. This was partly because the places where the Germans had the advantage (aircraft, communications, doctrine) were key. But it was also just that the leadership was so afraid of getting drawn into a repeat of WWI that they let themselves be overrun. It&#x27;s interesting to note that <i>nobody</i> expected the Germans to have that level of success, not even the Germans. Even Hitler, who was the optimistic one, thought they&#x27;d lose a million soldiers in that fight. I don&#x27;t know if you&#x27;re basing things off this experience, but it can&#x27;t be used to show that the Allies thought they couldn&#x27;t beat the Germans, nor probably even to show the Allies couldn&#x27;t actually beat the Germans if they had struck first.