I agree. Up until this year however there were no meaningful sanctions and the US bought 90% of Venezuelan oil

And the crash predates 2015 when the US put sanctions on individuals in the regime accused of crimes or human rights violations- that is to say on property and accounts of some officials

I have written much about the impacts of sanctions since the latest round and they have worsened the situation considerably. Check the date on the article.

I am also in Ecuador as we speak. You can find more info on that on my twitter and soon to have some videos out about it for Al Jazeera