I know that most Americans and Brits see their leaders of that time as heroes. Concerning the Polish question they were for sure not very heroic.
Too many Stalin-lovers in our State Department back then, unfortunately.
“Therefore it would have been worth a try not to betray the Poles.”
Failure to initiate WWIII against Russia with the Empire of Japan still intact and Germany in chaos doesn’t amount to betrayal. Using your logic, the United States betrayed not just Poland, but Czechoslovakia, Bulgaria, Romania, and all other nations living under Soviet oppression during the cold war. The U.S. weren’t even under obligation to liberate western Europe, much less all of Europe and Russia as well. You paint an unfair portrayal of America and her history by accusing her of betrayal.