1) As of 1939, Russia, or the Soviet Union (its successor), did not have a history of invading Western Europe for the purpose of conquest and subjugation. As of 1939, Germany did have such a history. 2) France and Britain realized that the invasion of Poland meant that Hitler’s territorial appetite could not be slaked by any agreement short of abject surrender. Their declarations of war against Hitler’s Germany were a matter of self interest, mixed with a bit of idealism. This is about as noble as any country gets.

Few are brighter than you. Great, great unexplored territory here. I can understand why it's so nettlesome. I suspect that the answer probably lies in the shame of their combined failure to meet their Polish defense obligations. Effectively prostrate and helpless before a German invasion of Poland, frightened beyond reason of the possibility of a German lunge westward, the French and British clearly accepted the partition as a fait accompli three weeks later when the Soviets crossed the eastern borders of Poland, believing that any further declaration of war was utterly empty of credibility, and therefore practically pointless. The Germans had already revealed the fundamental cowardice of both governments. With the fall of Chamberlain's gov't. in the spring of 1940, I'd be interested in the comments of Churchill about Stalin/the Soviet Union between April, 1940 and June 22, 1941. Remember, French communists actively opposed the defense of France in the spring of 1940, believing (ala le communista internationale)the Germans the friend of their friend (uncle Joe back at Party Central). Obviously, after June 22, 1941, everybody did their best to sweep this little embarassment under the rug. Great job, Kalaloch, to bring this back out into the light of day.

One part of this was the 'pessimism' of the French senior commanders. Leaders like Gamelin & Vuellimin (sp?) felt the French military could barely handle Germany, let alone take on another large industrial state. These men were even worried about Italy joining Germany. They discouraged the French politicians from allowing the war to expand. A second factor was the hope that the USSR could be brought into the war as an ally. In late 1938 or early 39 (cant recall which) English, French, & Soviet represenatatives had met for secret negotiations on a possible alliance vs Germany. No agreement was reached, but the Anglo/French politicians retained a forlorn hope the USSR could be presuaded at some later point. Last there is the idea that if the USSR has swiped some Polish cities, then at least the Germans dont have them.

Good question, I believe the answer is simply because they couldn't do anything about it. The two countries together weren't going to stop Germany, there was no chance of them ever restoring Poland pre-1939. As for the Soviet Union not having a history of attacking western Europe as stated by one poster, he might like to ask Finland about that. I won't mention Latvia, Estonia and Lithuania and a host of other countries whose sovereignty were apparently not important enough for either France of Britain. Interestingly it was Germany that came to the aid of Finland, managing to successfully hold out against the Red Army long enough to maintain its independence. Another interesting point is that Germany had legitimate territorial claims on Versailles granted territory to Poland including the 100% German city of Danzig. Furthermore, Poland was a dictatorship itself which contrasts with Czechoslovakia which the French and British sold down the river. If they were going to make a stand it should have been then. Their 'defense' of Poland was nothing other than bluster and a poor attempt at saving face. Poland itself was clearly unimportant because you're right, there wasn't a peep from either of the two countries when the Reds invaded.

Most European countries had spent the bulk of the 1930s fashoning their defense policy around the explicity stated threat from Stalin and the aggitation of communist groups in their European countries. Part of the muddle France got into prewar, circled around the centerist not know who to fear more Hitler or the threat from their own communist opposition parties. Many welcomed Hitler as a counter balance to Stalinist expansion. No doubt the non aggression pact took alot of people by surprise and in the end the Soviets alliance may have been seen like the Italian alliance. Up until 1936-37 Western diplomates actively courted Mussoline to join their side against Hitler...or atleast to avoid a 'block building' contest as occured prior to WW-I. Even up to the last few months before the war began, such diplomacy continued. Given that type of speed of diplomacy, I suspect the non aggression pact was such a surprise there was not really much time in diplomatic terms, to react. I seem to remember the consensus was that It was a 'devils pact' that would end up stabing one side in the back, so maybe diplomates attitude was to sit back and hopefully they would end up killing each other....it kind of happened that way anyways ;-)

Ibelieve that war wasn`t declared by England and France  on Russia is smple. Germany was the enemy that Versaille made them also F.D.R. told them not to declare with Russia. Idon`t believe for a minute that F.D.R. hadn`t conspired with the English to start  the war.