Ask Lemmygrad

Its quite obvious that they just didn't have the technical capacity to avoid it, and i don't think they have ever had. The US has been able to topple Venezuela for years they just weren't in a rush to do it nor they wanted to destroy their reputation yet, the US is now in a serious state of emergency economically and politically and thus accelerated these brutal takeovers without consideration for international reputation.

Same goes for Cuba, but the lack of economic resources there makes it a very low priority. Most of attempts against Fidel were made by ex-cuban extremists too