For many decades, roofing flux (a type of asphalt) from VZ was the preferred variety for making shingles in the US. Millions of tons of the stuff was shipped to US ports every year.
Then, Chavez put an end to these sales, in favor of sending it to his new buddies in China for a lower net back.
Genius !
I expect once we have a severe shortage of doctors Obama will trade with Cuba like Castro did with Chavez, and Castro did with Mugabe - doctors and teachers for oil. Doctors and teachers are an export commodity there.