Multi-domain operation is an US military advanced concept of approaching future military action, superior to joint operation, able to optimize the way the military force adapts to the specifics of new risks and threats to the security of states and alliances. The participation of the Military Sanitary Service and implicitly of the National Health System, as well as other military and civilian components, in multi-domain operations is important for maintaining the combat capacity of the staff and Forces, for caring for the sick and wounded, for coordinating medical countermeasures in operational situations, thus contributing to the success of the operation by minimizing health losses. The National Health System (NHS) includes all national, regional, local and individual entities that aim to maintain health, regain it and prevent disease in the entire population, including the Armed Forces of that state. The NHS includes state and private organizations, all of which work together and co-operate as needed to address local or national health crisis situations or engage in international aid (e.g. Red Cross). Moreover, the field of Human Medicine is integrated, through the new and realistic “One health” concept, with Veterinary Medicine, Animal Husbandry, Agronomy and Environmental Protection.