Alekpier608 said:
If the Western Powers promised to defend Polish Independence in 1939, why did they only declare war on Germany and not the USSR?
Realpolitic, but not quite for sure. Britain and Poland NEVER expected a Soviet attack. The alliance was directed towards German aggression, not against Soviet one.
Poland had anti-Soviet defensive alliance with Romania for that, but in 1939 Polish government officially didn't ask the Romanians to activate it - it was seen that they cannot help by getting beaten and neutral Romania was the priceless fall back area for over 100 000 Polish soldiers and its government.
Also the equipment bought by Poland before the war was on its way to Romanian ports - but Soviet attack made it useless - it was later used by Polish army in France nonetheless.
They were allied in the dismemberment of the Polish state.
That is tru. Soviet assisted Germany from the day one by helping them in certain ways like seting radio beacon in Minsk used by Luftwaffe. Germany also expected Soviet attack since 5th September and asked repeatedly why it doesn't come (German generals were afraid of French offensive very much).
I have never found anyone who can answer this question unless the Soviet Union, France, UK, and USA were already secretly united to destroy the Third Reich at some time prior to 1939.
They were not, thogh the Uk and France tried to involve Stalin into such alliance, but on conditions unacceptable to Poland - I cannot lose the feealing they were simply trying not to fight n their own and leave the dirty work to the others.
However after Poland was attacked, and more important after FINLAND was invaded and the SU was trown away from the League of Nations the UK and France prepared quite advanced plans to support Finland and to attack the Soviet Union DIRECTLY.
They considered Poland to be at war with the SU (which was tru, though complicated and blurred a little) so Polish Podhalan Brigade, navy and fighter units were supposed to fight in Finland transported through Scandinavia, there was also considerable British and French involvement, but I can't say what exactly.
Most likely it was of the sze of the force sent later to Narvik.
In addition - which is forgotten too often - British and French bombers were supposed to attack Baku oilfields and indeed recon flights were made from Syria and Iraq bases.
Soviets employed and American company to analise how dangerous would be such bombardment and those answered that flames would be very hard to extinguish - 'firestorms lasting for days' if I remember correctly.
British and French bombers made those recon flights and were impossible to intercept by Soviet fighters so such attack would be quite successfull, but before the Allies launched them Finland already signed the peace treaty.
It is possible that the danger of allied strike made the Soviets more willing to seek for agreement earlier than puppeting Finland as it was planned, but it might have no influence as well...
So the Allies might even go to war against the Soviets if such strikes were made and the situation was exploited more, but as usual their actions were 'too little too late', though theis aggressiveness is almost astonishing compared to lack of activity in 1939.
But after Russian and German Troops meet at Brest Livtosk as allies and Russia annexed the Baltic States, how can the British and France use the Invasion of Poland as a casus belli for DOW on Germany but not do anything to the USSR even after they attacked Poland, annexed the baltic states and invaded Finland. I don't know, it just doesn't seem to make sense to me. I have read bits and pieces of "Rise and Fall"... I will have to look it up.
There was one little detail I must add - British guarantees of independence were read and used as seemed fit by the British. The wording of te entire agreement was such that only independence of Poland was protected, but
NOT its territory - so according to the British if in the end Poland as a state was reduced to one small village it was still wht they promised.
Of course I am using 'reducing to absurd' rhetorical trick, but if we see later relations between Polish and British governments it is exactly what they did, though they failed to protect the independence as well, but that is another question.