The correct answer to this open question is the following.
How does this satellite and the Warsaw Pact provide a buffer for the Soviet Union?
Answer: These satellite countries allowed the Soviet Union some space and enough territories to be prepared and ready to defend Russia in the case some NATO nations wanted to send their armies to invade the USSR.
Joseph Stalin, leader of the Soviet Union, exerted political and economic control over satellite nations like Poland, East Germany, Czechoslovakia, Albania, Hungary, and Romania.