UNTSO is the first peacekeeping operation, established in May 1948 by the United Nations.
The UN had an important role in the attempt to solve the difficult situation in the Middle East. During the years, in response to the various conflicts in the area, the UN tried to create the conditions for a peaceful solution of the hostilities between Palestinians and Israelis, promoting several peacekeeping operations. In November 1947 the United Nations General Assembly promoted a project for the subdivision of Palestine, creating the conditions for an Arab State and a Jewish State; Jerusalem had to be considered at international status.
The plan was not accepted by Palestinians and the Arab Nations. On 14th May 1948 Great Britain abandoned its mandate in Palestine and later it was proclaimed the establishment of the State of Israel.
After a few days hostilities broke out between Israel and Palestinians (supported by the Arab States). On 29th May 1948 the Security Council adopted the Resolution 50 that ordered an immediate cease-fire in Palestine; it also established that the truce would be overseen by a UN Mediator assisted by international Military Observers.
The first group of the Observers, that constituted the "United Nations Truce Supervision Organization" (UNTSO), arrived to the region in June 1948.
In August 1949 the Security Council adopted the Resolution 73 that assigned new tasks to the UNTSO, after the "General Armistice Agreements" between Israel and the four Arab bordering Nations (Egypt, Jordan, Lebanon and Syria).
After the conflicts of 1956, 1967 and 1973, the functions and the tasks of the UNTSO Observers were modified in view of the change of scenery in the area; their presence as interposition force between the parties was also crucial as deterrent for a possible "escalation" resulting from isolated incidents. In the Middle East, groups of UNTSO Military Observers were deployed to support other peacekeeping Forces that operated in the area such as the "United Nations Interim Force in United Nations Disengagement Observer Force" (UNDOF) and the "United Nations Interim Force in Lebanon" (UNIFIL).
Italy contributed to the Mission with 7 Observers ( 6 from the Italian Army) and the mandate ended on 26th March 2015.