He nationalized the oil reserves and the rights for extraction of the oil.
Explanation:
Venezuela is a country that is very rich in oil, in fact it is the country that officially has the largest oil reserves in the world. Considering the fact that the oil is what brings in the majority of the income of this nation, plus the communist politics, Chavez nationalized all the oil reserves and the extraction of the same fall into the hands of the government. This angered the USA officials, as they are the biggest consumer of oil and always want to have control on the situation. Chavez though stood his ground, and that made the relations between the USA and Venezuela even worse, though in all fairness Venezuela has the right to do whatever it wants with its natural resources, so the USA has no right to tell them what to do or how should they do it.
