Since 2006, more than 30,000 Mexican citizens have died in drug-related violence. With the threat of this violence escalating and spilling across the border into the United States, it is necessary to employ the full range of assets and options available for the U.S. government to defeat or neutralize a growing national security threat to the safety and sovereignty of the United States. The Department of Defense possesses equipment and personnel with critical skills necessary to augment civil authorities' efforts to secure the U.S. border with Mexico. In this thesis, the researcher seeks to answer the questions of what role the Department of Defense should play in securing America's borders and which assets are best suited to Defense Support to Civil Authorities in border security operations.