On 29 May 1948, the United Nations Security Council, in its resolution 50 (1948) called for a cessation of hostilities in Palestine and established the first peacekeeping mission headed by a UN Mediator with the assistance of a group of military observers to be known as the United Nations Truce Supervision Organization (UNTSO). UNTSO is mandated to observe and maintain the unconditional ceasefires and assist the parties to the 1949 Armistice Agreements in the supervision of the application and observance of the terms of those Agreements. UNTSO’s mandate covers five countries, including Egypt, Israel, Jordan, Lebanon, and the Syrian Arab Republic. This position is located in the Security Section at UNTSO Headquarters, Jerusalem. The Field Security Assistant at the GS-3 level reports to the Guard Force Supervisor under the overall supervision of the Chief Security Officer / Deputy Chief Security Officer.