This thesis examines the rationale behind the Brazilian Army's attempt to establsih effective control of the Amazon through theCalha Norte project. The project was initiated in 1985 to satisfy geopolitical needs of Brazil. The thesis argues that the rationalefor Calha Norte has expanded to include not only geopolitical goals, but also a justification for the military's budget and legitimacy.Furthermore, the expanded rationale has resulted in the Brazilian army enlarging its prese,7e in the Amazon. Contrary to most ofthe literature, the thesis argues that the Calha Norte project has a favorable impact in the Amazon. The interests reviewed by thethesis include border conflicts, narco-trafficking and environmental conservation. Finally, the thesis recommends that Brazil expandthe Caiha Norte program, and that the United States support such an expansion.