They were hindered by economic development and lack of enforcement, so I'd say 1. Cost, because no one would pay for it.
Because They Could Not Attack A White Person Or The Cops Get Them
You could start off with the news report about how Soviet and U.S almost started another war due to a missile crisis with Cuba or how soviet's government is different from ours. Basically compare and contract Soviet and U.S.
Hopefully this can get you a head start
Have a great day :)