This first article is the launch of a monthly global health (GH) column for Military Medicine intended to catalyze thought and call for quantitative and qualitative analysis of defense and federal health engagement and its impact within the GH discipline. The U.S. Department of Defense (DoD) executes activities around the world that affect the health of United States and partner forces as well as civilian populations. More frequently the U.S. defense health community itself and others ask how these actions mitigate the global burden of disease, address complex GH issues, and meet the specific health sector needs of partner nations. U.S. defense capabilities have always been at the forefront of GH and preventive medicine issues such as vaccine development, tropical medicine, and water security. Some would express that although U.S. military health assets are employed internationally, they are only truly effective in combat casualty care and the acute phase of disaster response. Since U.S. defense global health engagement (GHE) has not employed the systematic approach expected in modern GH practice, it is challenged to prove positive impact in humanitarian assistance, health sector reconstruction, and peacetime development. DoD defines foreign humanitarian assistance in doctrine with good intentions, knowing that it cannot align fully with civilian humanitarian principles. DoD can add clarity to its role through improving strategic selection, intent, and planning of health engagement that could make measurement and sustainment more possible. Articles for this column will focus on tactical and operational level GHE. Purposefully designed activities should achieve long-term positive health and command objectives, but further objective analysis is needed to determine effects and validate processes. GH, as used by the development and academic communities, and GHE, as operationalized by DoD, are distinct concepts. GH is the modern version of the field of International Health with a definition that is accepted across academia, politics, and in the community of health experts. GHE, on the other hand, is a new term coined within the defense health community that encompasses the U.S. military activities that affect foreign health sectors. DoD is in the process of fielding an official policy definition of GHE but simple modification of the existing joint definition of military engagement will suffice for present discussion: “[Global health] engagement is the routine contact and interaction between individuals or elements of the joint [health] forces of the United States and those of another nation’s armed forces, foreign civilian authorities, or other agencies [with health sector impact] to build trust and confidence, share information, coordinate mutual activities, maintain influence, promote stability and security, and build partner capacity.” The most visible GHE is in international “disaster response” for either natural or manmade catastrophes when the civilian lead agency requests the military to participate in support. Military health assets are only requested in a small portion of declared emergencies, but these are usually large events with international attention, such that the DoD health response, positive or negative, gains significant visibility. DoD can benefit from a systematic, objective, approach to evaluation, continuous improvement, and the operationalization of lessons learned in disaster response. These efforts should be contemplated in the context of knowledge about disaster cycles, disaster epidemiologic data, the recipient nation health system, and geopolitical realities. Novel research needs to be conducted to produce evidence that helps support military decision makers in this endeavor. Likewise, the U.S. defense community has significant tools to assist a partnerati “disaster preparedness,” in military-tomilitary and military-to-civilian collaborations. State National Guard units and the Federal Emergency Management Agency provide deep domestic response experience that can be modeled and contextually adapted to assist a partner country in improving their domestic and regional capability. Validation of functional partner nation improvement in execution after U.S. preparedness assistance will be critical to determining how to proceed with future military humanitarian disaster preparedness programs. Department of Preventive Medicine and Biometrics, Uniformed Services University, 4301 Jones Bridge Road, Bethesda MD 20814. The views expressed are those of the authors and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences, The Department of Defense or the U. S. Government. doi: 10.7205/MILMED-D-15-00252