And why didnt they declare war on The Soviet Union when they invaded Poland?
Yes, Chamberlain signed the Anglo-Polish Agreement on 31 March 1939 to contain Nazi Germany. Sure, but why? And since Britain had guaranteed the rest of Czechoslovakia, why didnt they do anything when Germany invaded it?
And why did Britain want to contain Germany, but not the USSR?
Yes, Chamberlain may have led to WW2 by appeasing Hitler, but of course Hitler’s desire for “Lebensraum”, would have led to the nazis invading Czechoslovakia and Poland anyway.
But would that have led to WW2? I mean, did Hitlers plans include France? (Maybe, hard to tell)
Oh, incidentally, I learned that during the partition of Czechoslovakia, Poland went in and got a piece for itself, too.
And that Anglo-Polish Agreement ?
The Polish historian Paweł Wieczorkiewicz wrote, “Polish leaders were not aware of the fact that England and France were not ready for war. They needed time to catch up with the Third Reich, and were determined to gain the time at any price”. The publicist Stanisław Mackiewicz stated in the late 1940s, “To accept London’s guarantees was one of the most tragic dates in the history of Poland. It was a mental aberration and madness”. On the same day that Britain pledged its support of Poland, Lord Halifax stated, “We do not think this guarantee will be binding”.[citation needed] Another British diplomat, Alexander Cadogan, wrote in his diary: “Naturally, our guarantee does not give any help to Poland. It can be said that it was cruel to Poland, even cynical”.
Britain hadn’t signed an agreement with Czechoslovakia. What they had was a signed agreement with Germany that it wouldn’t invade the rest of Czechoslovakia.
The Soviet Union argued that the Polish government had collapsed and Poland no longer existed by September 17 when they crossed the border. So they said they weren’t invading Poland because there wasn’t a Poland anymore.
I don’t feel that held much weight. Britain and France clearly saw the Soviet Union as a different regime than the Russian Empire and they were hostile to the Soviet Union. For that matter, Britain had generally been pretty hostile to the Russian Empire. I think the basis for their decision in 1939 not to declare war on the Soviet Union was that they figured it would drive the Soviets more firmly into an alliance with Germany.
Well, and there’s geography. The USSR may have been considered a threat, but it was a threat way over there in Eastern Europe. They’d probably have taken years to invade all the countries between them and Western Europe before they became an immediate threat. But Germany was right in the thick of it. They could invade in pretty much any direction at any time, and the choice would have been entirely theirs. A far more immediate threat to deal with. That Hitler initially moved mostly eastward was all his own doing; he could have done something else.
The governments, maybe, but what about the people? The Allied nations had lost millions of lives to “the Hun” just a few years earlier. The public still had very strong feelings about the Germans in 1939, whereas their feelings about the Soviets were decidedly more mixed. A war against the U.S.S.R would have been much less popular than a war against Germany.
When the Nazis invaded Poland, it finally became clear to everyone that Churchill was correct in saying that you couldn’t make a deal with Hitler because Hitler was just going to keep on taking territory forever. Treaties and pacts and anything else that Hitler signed were just worthless paper.
The UK and France defeated Germany (and ended both the Austro-Hungarian and Ottoman empires) in the first world war, but that victory cost them so much that most French and British people would have done almost anything to avoid having to do the same thing again. Sadly, while they won the war, they lost the peace.
When Nazi Germany took Poland, nobody could fool themselves any more about what they were facing.
I think the popular feeling was that they didn’t want a war at all. The public was just coming to accept the idea that a war with Germany was inevitable even if they didn’t want it. I don’t think there was a similar feeling towards the Soviet Union.
Because they weren’t obligated to. Quote from Wikipedia on the pact.
“In a secret protocol of the pact, the United Kingdom offered assistance in the case of an attack on Poland specifically by Germany,[3] but in the case of attack by other countries, the parties were required only to “consult together on measures to be taken in common”.”
Because the German occupation of the rump of Czechoslovakia finally confirmed for those who wanted to avoid war that Hitler wasn’t just unifying German-speakers. Obligating the UK to Poland was intended as a warning to Hitler.
At that point there was no reason to suppose Stalin was planning any sort of agreement with Hitler, and when it came (months later) the plan for the USSR to occupy eastern Poland was still secret, until it actually happened. By that time it was clear there wasn’t much Britain and France could do to support Poland against Germany, and therefore even less against the USSR.
The idea was that Hitler might be willing to go to war with Poland by itself. But he might not be willing to go to war with Poland if it also meant going to war with Britain and France.
Spoiler: He was.
But the overall idea was that Britain and France were hoping to prevent a war.
Which lesson amounts to: your defensive alliance needs to be overwhelmingly obviously more powerful than the would-be attacker. Not just at rough parity, or worse yet, slightly below parity.
And even then it only works when the attacker doesn’t mistakenly apply too much of a discount to your side’s military power & prowess versus their own. And when the attacker isn’t simply an insane psychopath.