Yes, Stalin had an alliance with Hitler until Germany launched Operation Barbarossa in May of 1941.
The British and French were preparing an expedition to land in Norway and march to Finland to assist the Finns in fighting the Soviet invasion of Finland in the winter and early spring of 1940.
When the Germans invaded Norway, this force ended up in Narvik in an attempt to defend northern Norway from the Germans. It was withdrawn when the Germans invaded France proper.
I suspect this phrasebook may have its orgins in that whole affair. I'm sure the author of the piece was indeed utterly clueless.
"The book was dated 1940. Sounds to me more like Stalin was preparing the Red Army to take part in Operation Sea Lion along with his Nazi allies."
Which underscores what great heroes the outnumbered RAF pilots were in defeating the Luftwaffe in the Battle of Britain. The defeat of the RAF had to happen first before Operation Sea Lion could be put into effect. Think what might have happened had the RAF been defeated! Could the US have defeated a Europe and Britain entirely in the hands of a Hitler/Stalin alliance? Scary thought indeed.
Never was so much owed to so few.
June 1941 ... June 22, 1941