Energy relations have been a major element in the U.S.-Mexico relationship over the past few decades but may wane as an issue of importance in the coming years.
Morales, Isidro. "The Energy Factor in Mexico-U.S. Relations." (2011) James A. Baker III Institute for Public Policy of Rice University: http://bakerinstitute.org/research/the-energy-factor-in-mexico-us-relations/.