Russia lost 23,000,000 people in World War II. Europeans have attempted invasions of that country several times throughout history, but were foiled due to harsh weather and the tenacity of the Russian people.
After WWII Russia decided that they needed to insulate the motherland. They established the USSR and absorbed bordering countries in a number of different ways. Invaders would have to take a neighboring country before getting to Russia and they stacked defensive equipment in all of those countries. The west responded by stacking their own assets on allied borders, kicking off an escalation called The Cold War.
Here are a couple of classic tracks from Sting and Al Stewart about Mother Russia. Don’t forget to tune in to The Americans on FX. A good show about embedded KGB agents set in the 1970s.