The National Defense Service Medal (NDSM) is a service medal of the United States Armed Forces established by President Dwight D. Eisenhower in 1953. The medal was first intended to be a "blanket campaign medal" awarded to service members who served honorably during a designated time period of which a "national emergency" had been declared during a time of war or conflict. It may also be issued to active military members for any other period that the Secretary of Defense designates.
Currently, the National Defense Service Medal is the oldest service medal in use by the United States Armed Forces. The oldest continuously issued combat medal is the Medal of Honor.