I want to know the answer to the following question:
Why did western power believe that the soviet government wouldn’t partake in another world war?
All the background I'm provided with is that "Britain and France believed that war could still be avoided, and that the Soviet Union, weakened by the Great Purge, could not be a main military participant, a point that many military sources were at variance with, especially Soviet victories over the Japanese Kwantung army on the Manchurian frontier.". Is that enough to answer the question?
Answer: yes