posted by cat .
i need ti write a paper on why the soviet union is to blame for the cold war. could an example i cit be when the soviet union invaded afghanistan?
You need to go farther back in time than the Soviet invasion of Afghanistan. Start with the end of World War II.
These sites should help you.
why do i need to do that? I have to focus on events of the 1970s and 1980s
Blame is usually attached to the beginning of a conflict. However, the articles above detail the Cold War in the 70s and 80s so you should find lots of information there.