The purpose of this study is to explain the Bolivian decision of nationalization of its hydrocarbons and the Brazilian moderate answer since the perceptions of Evo Morales and Lula about the changes on the distribution of capacity of the actors. The hypothesis to be verified considers that Bolivia decided to nationalize its hydrocarbons once its decider realized systemic transformations which guarantee Bolivia a more favorable position inside regional status quo. A few transformations are the crescent world demand for energetic resources and its consequent raise of prices, the increase of the Brazilian dependence for gas supply, and besides, the Venezuela s growth in the regional scenario and its support to Bolivia, threatening the Brazilian regional leadership and destabilising the regional integration process. At the same time Brazil had chosen to react in a moderate way once the president Lula also had realized these transformations and how his capacity of keeping his position inside anarchy had diminished, being caution necessary in answer given to the Andean country.