Perhaps you could be the one to explain why securing for Poland both the promises of free and fair elections and the movement of Poland's western borders to those first proposed by the Polish leader of the time is something which the British should be ashamed of?
You might ask the same question to former British PM Harold Macmillan, who famously wrote, ""No Englishman or American can read this record without a sense not only of sympathy, but of something like shame." Macmillan wrote these words in the forward of General Anders's memoir,
An Army in Exile: The Story of the Second Polish Corps (Allied Forces Series):
These are the men who served time in the Soviet Gulags in Siberia, then returned to fight with the Brits in the West, did so even after learning of the betrayal of Polish-British prewar treaty out of loyalty to their Allied brothers-in-arms with whom they fought, and where then denied recognition in the British victory parade, so as not to offend Stalin.
In fairness to Macmillan, he was writing in the present tense when he wrote that forward to General Anders's book. Macmillan cannot be held accountable for the ignorance of modern Brits about the history of the war, since some inconvenient truths are omitted and other excuses made for the commitments which were clearly never kept.
The shame here consists of two distinct points: 1) the U.K. had betrayed Poland, and the other 2) that the U.K. left the Poles under Soviet control after the war. Citing the Yalta agreement does not address the first point, since the U.K. and France failed to honor their treaty agreements to attack the Germans within two weeks of an attack on Poland:
(See also, Count Edward Raczyński (1948). The British-Polish Alliance; Its Origin and Meaning. London: The Mellville Press.)
Did the Brits in fact lend "all support in their power" in September 1939 to Poland?
Someone please tell us how the Brits supported the Polish war effort against the Nazis in September 1939.
The fact remains that Hitler left Germany's Western border unguarded while he attacked Poland, but no Anglo-French attack was forthcoming. The French ate cheese and drank wine, while the Brits simply told Hitler, "Adolf, you are a very naughty boy." It is called "The Phoney War" for a reason.
Until the year 1939, we were, of course, in a position to destroy Poland alone. But we were never, either in 1938 or 1939, actually in a position to withstand a concentrated attack by these States together. And if we did not collapse in the year 1939, that was due only to the fact that during the Polish campaign, roughly 110 French and British divisions in the West were completely inactive as against the 23 German divisions.
When I studied the issue, from several different perspectives in different courses, there wasn't a single professor or writer who questioned this point.
Since the RAF had dropped propaganda leaflets on German cities in 1939, they also could have dropped bombs, but of course, that is just my humble opinion. Since the British did nothing of note to help the Poles in September 1939, any help would have been useful. There is a reason that the press called the Western war, the "Phoney War", the "Bore War" and the "Sitzkrieg". Chuchill himself called in the "Twilight War", since Poland's Western allies did nothing to fulfill their treaty obligations.
The second point is that the U.K. had left the Poles under Soviet domination after the war:
So how many Poles would have fought in North Africa, Italy, the Western front, etc., defended the skies in the Battle of Britain, and fought on the seas from the start of the war to its finish if they had known what would eventually happen? The British government kept their agreements with the Soviets secret because it was well known the affect it would have on the Poles fighting side-by-side with the Anglo-American forces. Tell us how proud you limies are of that!
Citing the Yalta agreement is hardly dispositive of anything. It was the Tehran Confernce which had proposed using the Curzon Line as Poland's border with the USSR. However, there were in fact two Curzon Lines, A and B. Line B had kept Lwow inside the borders of Poland, and Lwow had been a Polish city for 600 years. Lwow best exemplifies what happened to Poland because of the war. The entire city is an unmarked crime scene of crimes against humanity on a massive scale: Ethnic cleansing of its Jews and Poles, forced deportations by an occupying power, and deprivation of freedom of religion to its Ukrainian speaking Catholics who were forced to renounce the Pope by Stalin. Nothing was done by the Brits and Americans to keep Lwow in Poland, and they did have sufficient leverage over Stalin during the war since the communist system by itself couldn't produce enough guns and trucks to win a war.
Please provide proof that a Polish leader had agreed to the border change, without Polish consent. Being open to negotiate a swap of land in Belarus or Volynia for German lands is not the same as having agreed to the annexation of cities which were Catholic with Polish speaking pluralities of their populations. No Polish leader could have agreed to that, and would not.
