This paper seeks to demonstrate the complex security nexus among sovereignty, borders and energy resources through a case study on the dispute over the Peru-Ecuador border. The territory in dispute has both a historical and economic importance for the two countries, since it is rich in natural resources. The dispute erupted over poor border demarcation during the decolonisation period and independence, as elsewhere in Latin America, leading to disputed sovereignty over it. However, the evidence over the presence of oil and gas underneath this geographical space led to a series of militarised conflicts between the two states, and further violations of state sovereignty. This paper will address the securitisation of the disputed border through a Schmittian understanding of sovereignty as the ability to decide on the exception and will further demonstrate the complex constitution of borders as security spaces.