Stalin and World War II

I've been having discussions alot lately with one of my classmates about marxism-leninism, Soviet history, etc., and one thing that grabbed his attention was the Soviet Union's role in the second World War. I'm planning to give him a big bundle of stapled packets on marxism-leninism to get him started on theory, and I'd like something short yet provocative about Stalin and the Soviet victory over fascism to add in as a bonus. Can anyone think of something for me to give him along these lines? Thanks in advance, comrades.

The most troubling fact of WW2 is that Stalin purged 90% of his generals and admirals and over 50% of the CP. This is probably why he lost so much ground in the first two years. However a friend of mine said that the purges of the generals and of the party were necessary. He said that during the Revolution it was necessary to include all types of untrustworthy elements into the leadership in order to win. This meant Stalin had to kill, not just fire these leaders, since these people were trained to command and kill and had learned all the jargon to appear as Red leaders which made them doubly dangerous. Any comments or are there better reasons?

You seem to me making some pretty bizarre claims that not even the most extreme anti-communists claim. In fact the reality is as follows:

During the 1937-38 purges, 34,300 officers and political commissars were expelled for political reasons. By May 1940, however, 11,596 had already been rehabilitated and restored to their posts. This meant that during the 1937-38 purges, 22,705 officers and political commissars were dismissed (close to 13,000 army officers, 4,700 air force officers and 5,000 political commissars), which amounts to 7.7% of all officers and commissars - not 50% as Conquest alleges. Of this 7.7%, some were convicted as traitors, but the great majority of them, it would appear from historical material available, simply returned to civilian life.

Some people entered the Communist party for reasons other than for socialism or for serving the working class, some were in the party out of self interest or some went as far as sabotage. And keep in mind in 1930 about 10% of the officer were actually former officers from the Tsarist Army.