Tidwell says that Davis felt betrayed when Soviet dictator Stalin signed the 1939 nonaggression pact with Nazi Germany, which triggered World War II, but that Stalins eventual decision to join the U.S. and its allies in a war on the Axis powers restored a measure of Davis confidence in the USSR.
Stalin's decision? Hitler made that decision for him when he double crossed Uncle Joe and invaded the USSR. Stalin would have been quite happy to stay on the sidelines and pick up the pieces after the rest of the world ruined itself.
And if he lived til the present, he would witness their reemergence.