This monograph answers the question, Is the National Guard (NG) Counterdrug (CD) Support Program a suitable model to design an NG Homeland Security (HLS) force also capable of fulfilling the National Guard's role as a first military responder and maintaining a warfighting capability as a federal ready reserve force? In February 2001, the U.S. Commission on National Security/21st Century recommended that the National Guard (NG) fulfill a primary role in HLS and posture to assist first responders and provide state governors with immediate command and control capability tied to a National Crisis Action Center. Following the Hart-Rudman study, Department of Defense (DOD) agreed HLS was the NG's responsibility, however an NG HLS program was not yet initiated or funded. The horrific September 11, 2001 attacks accentuated the vulnerability of the United States to transnational threats. The attacks instantaneously resulted in unprecedented change in global security posture, thrust many of the national security recommendations into action, and released funding for HLS initiatives and immediate domestic security needs. Aware that the NG is accustomed to operations with state and local agencies and working as a joint first military responder under the Governor's state response plan, the researcher sought a method to identify domestic HLS requirements that could address transnational threats such as terrorism. This led the author to the established NG CD support program for comparative analysis, a program developed to contend with the transnational threat of illicit drug trafficking. To answer the question, the researcher conducts through a historical overview of the NG, two DTLOMS analyses, and a comparative analysis to determine parallels and shortfalls between the NG CD program and the requirements for an NG HLS force. The overview describes the founding of the militia, the dual role of the NG, and how the NG has played a major part in military operations both at home and a