I would not say it was a hoax as there was certainly animosity between the communist soviets and capitalist countries. However, it's quite clear that the military industrial complex and other entities benefited from it. I think that those interests always want the USA to have a clear enemy in order to produce more weapons and get more funding as the Cold War was replaced by the War on Terror in the 2000s and now we have Cold War 2.0 with Russia as the new bogeyman.