Not all of WW2 - they jointly invaded Poland:
http://en.wikipedia.org/wiki/Molotov%E2%80%93Ribbentrop_Pact
It was after the Soviet invasion of Poland that the infamous Katyn Massacre occurred:
http://en.wikipedia.org/wiki/Katyn_massacre
Which included 7000 prisoners executed by a single man:
Given the numbers, saying Russia and Germany were on opposite sides in WW2 seems pretty accurate to me.
He doesn't even know about alternative theory of Khatyn's massacre because Wikipedia doesn't say so.
Since you mention Wikipedia, are you suggesting all of the below are false as well?
http://en.wikipedia.org/wiki/Soviet_invasion_of_Poland http://en.wikipedia.org/wiki/Winter_War http://en.wikipedia.org/wiki/Occupation_of_the_Baltic_states
Mindless pedantry is one of the most irritating features of "hackers". Yes, we know you know a lot of stuff. Do you expect us to be impressed?
I believe it's usually because they focus on a single battle, a specific zone and/or a specific time. That title helps the buyer quickly know what the game is about (Wargamers are, many times, history buffs)
[EDIT] I stand corrected. I sometime get lost in the tree-like way the replies are showed.
While Hitler was busy carving up Poland, he was planning the entire time for how to bring Russia to its knees. At no point did he plan for anything but eventual confrontation with Russia.
If I give you a ride home today, while plotting your demise for tomorrow, we're not pals.
However, I think that's a silly distinction to make - you can't just swap nations in every game, since the game mechanics for managing a Soviet nation or army could well be different from those of managing the 3rd German Empire.
But the article doesn't say much about the game, so I don't know if this was the case.