on Sept 1,1939 Germany & Soviet Union invaded Poland, UK declared war to Germans, why not to both of them?

Question

shoudnt British have declared war to Soviet union too?

Answer 1

To correct your question, the Soviet Union did not invade Poland on 9/1/39.

Rather the sequence was:
9/1/39 - Germany invades Poland
9/3/39 - Britain and France declare war on Germany
9/17/39 - Soviet Union attacks Poland

http://www.csub.edu/~mbaker2/Hist102WWIItxt.htm

A week before the invasion, Germany and the Soviet Union sign a Nonaggression Pact. Germany signed this so that the Soviet Union would not declare war on Germany for its imminent invasion of Poland, averting an early two-front war. The Soviets signed because a secret protocol of the pact gave the Soviet Union the Baltics and a third of Poland.

http://history1900s.about.com/library/holocaust/aa072699.htm

So, when the Soviets attacked Poland, they did not do so as a formal ally of Germany. And it wasn't much of an attack - more of a forced occupation. The Polish forces were pretty well decimated by this time.

Although the USSR was complicit in the invasion, it was not acknowledged until well after the war.

If the Allies had known of Soviet complicity in the invasion, there may have been a different response to the Soviet movement into Poland.

Answer 2

First thing was that Britain's and France's declarations of war were made on 3 September, but the Soviet invasion started on 17 September, so it was unlikely that a simultaneous declaration was possible. I would guess that the declaration of war with Germany was a result of Germany's earlier conquests of Austria and Czechoslovakia, while the Soviet Union did not have that belligerent history. I would also suppose that the matter of proximity was an issue. Lastly, I suspect that the non-aggression pact that Germany and the USSR had signed in August 1939 was not expected to last, so there was a reason to not antagonize a possible future co-combatant.

Still, it is a very good question. With attacks on Finland and the Baltic States, it did seem that the USSR got a free pass from the Western Allies at the time. Thanks for the interesting thought exercise.

Answer 3

Britain and France had publicly and loudly proclaimed that they were through appeasing Germany's territorial ambitions. After watching Germany unify with Austria, annex the Sudetenland and then assimilate the rest of Czechoslovakia, the western powers had made it clear that they would not tolerate any more GERMAN adventurism in central or eastern Europe and thereby guaranteed the integrity of Poland's borders against German aggression. They had not made any similar guarantees against Soviet aggression. Had they forseen the problem, they might have taken a different stance. However, Stalin was an anti-fascist, and Hitler was an anti-communist. The nazi-soviet pact which partitioned Poland between them was a secret treaty that Britain and France did not know about and could not have reasonably forseen. Also, when the Soviets crossed into Poland, it was somewhat surreptitious, and even when their presence was known, it wasn't immediately clear why they were there. Soviet intervention could have appeared as opposition to the German invasion, aid to Poland, or sheer opportunism...

Answer 4

Because the Soviets didn't declare war until later in the month (remember the Nazi Soviet alliance of August 1939 which carved up Poland between the two nations)

Answer 5

The Germans invaded Poland but the Soviets didn't. The Soviet Union was actually allied with the U.K. and the U.S. It took the whole world to beat the Germans off except for Italy who were unwilling allies of Germany.

Answer 6

Germany by invading Poland was blatantly breaking the terms of the WW1 Armistice and hence not just an aggressor but a repeat offender! Russia dispite a non-aggreeeion pact with Germany was still on good terms with England and had not shown the zeal for war the Germans had!

Answer 7

The Soviets didn't, I think Germany promised to give the Soviets control of eastren Poland if the invasion succeded. Of course, we all know that germay backstabbed them and invaded their country as well

Answer 8

At the time, everybody knew the Germans were the real threat. Also, the Soviet invasion was seen as prophylactic.

Answer 9

the soviet union was the uks ally.

Answer 10

You don't declare war on countries you can't fight and beat.

This intelligent credo has been ignored by amongst others, Napoleon (on England), and Hitler (on the USA)

The USA never declared war on Vietnam, or on Iraq, so this rule does not apply to the USA.