The first United Nations Service Medal was created in December, 1950 in response to the North Korean invasion of the Republic of Korea—this in spite of the fact that this U.N. intervention had been preceded by two operations that were launched more than a year before the outbreak of the Korean War.
With the passage of time and the realization that an organization dedicated to the peaceful resolution of conflicts between nations was no guarantee that peace would be maintained, the United Nations finally established what might be called the “standard” U.N. medal. According to Executive Order 11139 issued January 7, 1964, the United Nations created this new medal on July 30, 1959; the Executive Order was to reign in issuance of the medal to U.S. Servicemembers by having the Secretary of State determine that military service with the U.N. in “a particular geographic area or for a particular purpose constitutes a justifiable basis for authorizing acceptance of the United Nations Medal and Service Ribbon by eligible members of the armed forces of the United States.”
There are two aspects that determine whether members of the Armed Forces of the United States are authorized to wear the United Nations Medal or Ribbon for their role in a given U.N. action or mission. First, the Department of Defense must approve the mission; second, individuals must serve under the control—either operational or tactical—of the U.N. for a minimum of ninety consecutive days. Eligible Members of the U.S. military are awarded a U.N. Medal by the Chief of the U.N. Mission.
As of 2015, there are nearly three dozen U.N. Missions and Actions for which the organization has created ribbons that the Department of Defense has authorized acceptance for wear by members of the United States Armed Forces. Of these, a full third (twelve) have end dates that are yet to be determined, including the very first two approved of by DoD: the U.N. Truce Supervisory Organization in Palestine and the U.N. Military Observers Group in India and Pakistan.
The most recently DoD-approved U.N Mission is the U.N. Multidimensional Integrated Stabilization Mission in Central African Republic, or MINUSCA. Launched on April 10th, 2014 and approved by the Department of Defense on September 26 of that same year, the mission has been designed to help the African Union’s MISCA peacekeeping force help establish the UN’s MINUSCA as a more effective peacekeeping operation.