To what extent do you agree Soviet Foreign Policy from 1900-1991 was mainly driven by security concerns?

According to Rack, Soviet Foreign Policy was not mainly driven by security concerns but indeed mostly by ideological fantasies of the leaders to expand Communism. However, I would tend to disagree with the proposition and Rack and support Haslam when he states that security drove Soviet Foreign Policy during this time period.

(This is a 1 hour 15 mins essay, the paragraph above is only an introduction)