Establishment of UNYOM
Mandate extensions
Organization of UNYOM
Special Representative appointed
Secretary-General's assessment
Termination of UNYOM


A civil war which broke out in Yemen in September 1962 contained the seeds of a wider conflict with international dimensions because of the involvement of Saudi Arabia and the United Arab Republic. Saudi Arabia shared an extended border with Yemen, much of it still undefined. The United Arab Republic (Egypt) had had a special relationship with Yemen in the past. In March 1958, Yemen joined it to form the United Arab States, but this association was dissolved in December 1961, shortly after Syria seceded from the United Arab Republic. A further factor in the situation was that Yemen had long claimed that the Aden Protectorate was legally part of its territory. The British-controlled Government of the South Arabian Federation, which included the Aden Protectorate, therefore also closely followed developments in Yemen.

On 19 September 1962, Imam Ahmed bin Yahya died and was succeeded by his son, Imam Mohammed Al-Badr. A week later, a rebellion led by the army overthrew the new Imam and proclaimed the Yemen Arab Republic. The new Government was recognized by the United Arab Republic on 29 September and by the Soviet Union the next day, but other major Powers with interests in the area, including the United Kingdom and the United States, withheld action on the question of recognition.

Following his overthrow, Imam Al-Badr managed to escape from San'a, the capital, and, with other members of the royal family, rallied the tribes in the northern part of the country. With financial and material support from external sources, the royalists fought a fierce guerrilla campaign against the republican forces. The revolutionary Government accused Saudi Arabia of harbouring and encouraging Yemeni royalists, and threatened to carry the war into Saudi Arabian territory. The Imam, on the other hand, claimed that the army rebellion was fostered and aided by Egypt, which denied the charge. At the beginning of October, large numbers of United Arab Republic forces were dispatched to Yemen at the request of the revolutionary Government to assist the republican forces in their fight against the royalists.

On 27 November, the Permanent Mission of Yemen to the United Nations, which was still staffed by the royalists, addressed a letter to the Secretary-General urging the United Nations to establish an inquiry to ascertain whether or not the rebellion was fostered from Cairo. This letter was informally circulated to the United Nations missions. A delegation of Yemeni republicans which had arrived in New York by that time let it be known that they would not object to a United Nations on-the-spot investigation.

The General Assembly, which began its seventeenth session in New York in September 1962, had before it credentials from both the royalist and republican regimes in Yemen. It took up the question of the representation of Yemen on 20 December, the very last day of its session. On that day, the Credentials Committee decided, by a vote of 6 to none, with 3 abstentions, to recommend that the Assembly accept the credentials submitted by the President of the Yemen Arab Republic. Later on the same day, the Assembly approved, by 73 votes to 4, with 23 abstentions, the Committee's report.

King Hussein of Jordan earlier that month had suggested that the presence of United Nations observers might be useful in finding a solution.

Establishment of UNYOM

Secretary-General U Thant undertook a peace initiative, which eventually led to the establishment of the United Nations Yemen Observation Mission (UNYOM).

In a report dated 29 April 1963, the Secretary-General stated that, since the autumn of 1962, he had been consulting regularly with the representatives of the Governments of the Arab Republic of Yemen, Saudi Arabia and the United Arab Republic about “certain aspects of the situation in Yemen of external origin, with a view to making my office available to the parties for such assistance as might be desired towards ensuring against any developments in that situation which might threaten peace of the area”. He had requested Mr. Ralph J. Bunche, Under-Secretary for Special Political Affairs, to undertake a fact-finding mission in the United Arab Republic and Yemen. As a result of the activities carried out by Mr. Bunche on his behalf, and by Mr. Ellsworth Bunker, who had been sent by the United States Government on a somewhat similar but unconnected mission, he had received from each of the three Governments concerned formal confirmation of their acceptance of identical terms of disengagement in Yemen.

Under those terms, Saudi Arabia would terminate all support and aid to the royalists of Yemen and would prohibit the use of Saudi Arabian territory by royalist leaders for carrying on the struggle in Yemen. Simultaneously with that suspension of aid, Egypt would undertake to begin withdrawal from Yemen of the troops that had been sent at the request of the new Government, the withdrawal to be phased and to take place as soon as possible. A demilitarized zone would be established to a distance of 20 kilometres on each side of the demarcated Saudi Arabia–Yemen border, and impartial observers would be stationed there to check on the observance of the terms of disengagement. They would also certify the suspension of activities in support of the royalists from Saudi Arabian territory and the outward movement of the Egyptian forces and equipment from the airports and seaports of Yemen.

The Secretary-General asked Lieutenant-General Carl C. von Horn (Sweden), Chief of Staff of the United Nations Truce Supervision Organization (UNTSO), to visit the three countries concerned to consult on the terms relating to the functioning of United Nations observers in implementation of the terms of disengagement.

In a second report dated 27 May, the Secretary-General told the Council that on the basis of information provided by General von Horn, he concluded that United Nations observers in the area were necessary and should be dispatched with the least possible delay. The personnel required would not exceed 200, and it was estimated that the observation function would not be required for more than four months. The total cost was estimated to be less than $1 million, and he hoped that the two parties principally involved, Saudi Arabia and Egypt, would undertake to bear this cost.

In a further report submitted on 7 June, the Secretary-General informed the Security Council that Saudi Arabia had agreed to accept a ‘proportionate share” of the costs of the operation, while Egypt agreed in principle to provide $200,000 in assistance for a period of two months, which would be roughly half the costs of the operation for that period. Thus, there would be no financial implications for the United Nations in getting the Observation Mission established and for its maintenance for an initial two-month period. The Secretary-General announced his intention to proceed with the organization and dispatch of the Mission without delay.

The next day, the Soviet Union requested the convening of the Council to consider the Secretary-General's reports on developments relating to Yemen. After considering the reports, the Council adopted, on 11 June 1963, resolution 179 (1963), requesting the Secretary-General to establish the observation operation as he had defined it. This resolution constituted the basis for the establishment of UNYOM. It did not set a specific time-limit for the Mission, although two months was mentioned in the preamble in connection with its financing. The Secretary-General took the position that he could extend UNYOM without a decision of the Security Council if he considered that its task had not been completed, provided that he could obtain the necessary financial support.

Mandate extensions

In his first report on the operation, which was submitted to the Security Council on 4 September 1963, the Secretary-General pointed out that the Mission's task would not be completed on the expiration of the two-month period, and for that reason he had sought and received assurances from both parties that they would defray the expenses of the operation for a further two months.

In his second report dated 28 October, the Secretary-General reported that there had been no decisive change in the situation in Yemen and, because of the limiting and restrictive character of the UNYOM mandate, the Mission would have to be withdrawn by 4 November 1963, since there would be no financial support for it after that date. However, three days later, he informed the Council that Saudi Arabia and Egypt had agreed to participate in the financing of UNYOM for a further two-month period and, accordingly, preparations for the withdrawal of the Mission had been cancelled. He indicated that, although no Security Council meeting was required for the extension of UNYOM, he had consulted Council members to ascertain that there would be no objection to the proposed extension.

On 2 January 1964, before the expiration of the third two-month period, the Secretary-General reported that he considered that the continuing functioning of UNYOM was highly desirable, that the two Governments concerned had agreed to continue their financial support for another two months, and that he had engaged in informal consultations with the members of the Council before announcing his intention to extend the Mission. This process was repeated at the beginning of March, May and July 1964, and UNYOM was extended for successive periods of two months until 4 September 1964.

In late August 1964, Saudi Arabia informed the Secretary-General that it found itself unable to continue the payment of expenses resulting from the disengagement agreement, and Egypt indicated that it had no objection to the termination of UNYOM on 4 September. The Secretary-General therefore advised the Council of his intention to terminate the activities of the Mission on that date.

Organization of UNYOM

Following the adoption of resolution 179 (1963), the Secretary-General appointed General von Horn as Commander of UNYOM and took steps to provide the Mission with the required personnel and equipment. In the initial stage, UNYOM was composed mainly of six military observers, a reconnaissance unit of 114 personnel and an air unit of 50 officers and men. In addition, 28 international staff members and a small military staff were assigned to UNYOM headquarters. The military observers were detailed from UNTSO and the reconnaissance unit personnel were drawn from the United Nations Emergency Force (UNEF). The UNEF air base at El Arish provided support for the air unit, including six aircraft and a similar number of helicopters.

With the arrival of General von Horn and the first group of military personnel, UNYOM began operations on 4 July 1963. In August, General von Horn resigned, and his deputy, Colonel Branko Pavlovic (Yugoslavia), took over as acting Commander until September 1963 when Lieutenant-General P. S. Gyani (India), then Commander of UNEF, was temporarily detailed from that Force and appointed Commander of UNYOM.

The strength and composition of UNYOM remained unchanged until November 1963, when a reappraisal of its requirements in terms of personnel and equipment was undertaken. It was felt that in view of the cooperation shown by the parties and the peaceful and friendly attitude of the people in the area covered by the Mission, it was no longer necessary to maintain a military unit in the demilitarized zone; therefore, it was decided to withdraw progressively the reconnaissance unit and to deploy instead up to 25 military observers, while the aircraft of the Mission were reduced to two.

Special Representative appointed

At the end of October 1963, when the Secretary-General thought UNYOM had to be withdrawn for lack of financial support, he announced his intention to maintain a civilian presence in Yemen after the withdrawal of the Observation Mission, and he had in mind the appointment of Mr. Pier P. Spinelli, head of the United Nations Office at Geneva, as his Special Representative for this purpose. After the withdrawal plan was cancelled, as mentioned earlier, the idea of appointing Mr. Spinelli was retained, particularly since General Gyani had to return to his command in UNEF.

In November 1963, upon the departure of General Gyani, Mr. Spinelli was appointed Special Representative of the Secretary-General, as well as head of UNYOM. He assumed this dual responsibility until the end of the Mission.


The mandate of UNYOM stemmed from the disengagement agreement entered into by the three Governments concerned, namely, Saudi Arabia, the United Arab Republic and the Arab Republic of Yemen, set out in the report of the Secretary-General of 29 April 1963. The function and authority of UNYOM as defined in the agreement were considerably more limited than in the case of other United Nations observation missions. For example, its establishment was not based on any ceasefire agreement and there was no ceasefire to supervise. The tasks of UNYOM were limited strictly to observing, certifying and reporting in connection with the intention of Saudi Arabia to end activities in support of the royalists in Yemen and the intention of Egypt to withdraw its troops from that country.

To carry out these tasks in the initial stage, detachments of the UNYOM’s reconnaissance unit were stationed in Jizan, Najran and Sa'dah in the demilitarized zone and the surrounding areas. They manned check-posts and conducted ground patrolling. In addition, air patrolling was carried out by the air unit, which had bases at San'a as well as Jizan and Najran, particularly in the mountainous central part of the demilitarized zone where there were few passable roads. The six military observers detailed from UNTSO, who were stationed at San'a, and the two positions at Al Hudaydah were primarily responsible for observing and certifying the withdrawal of Egyptian troops.

In order to check on the reduction or cessation of assistance from Saudi Arabia to the royalists, a pattern of check-points and air/ground patrolling was established to cover all main roads and tracks leading into Yemen and the demilitarized zone. Air and ground patrols were carried out daily with varied timings and routes, the patrol plan being prepared and coordinated every evening.

Experience quickly showed that air and ground patrolling had two main limitations, namely, that traffic could be observed only by day while, for climatic reasons, travel during hours of darkness was customary in the area, and that cargoes could not be checked. These problems were met by periodically positioning United Nations military observers at various communication centres for 40 hours or more, so that traffic could be observed by day or night and cargoes checked as necessary. Arrangements were also made to have Saudi Arabian liaison officers assigned to United Nations check-points and check cargoes when requested by United Nations observers.

Various complaints were received by UNYOM from one or the other of the parties concerned. They fell mainly into two categories: on the one hand, allegations of offensive actions by Egyptian forces against the royalists in Yemen and in Saudi Arabian territory, and, on the other, alleged activities in support of the royalists emanating from Saudi Arabia. UNYOM authorities would transmit these complaints to the parties involved and, whenever possible and appropriate, investigate them.

In accordance with the disengagement agreement, the responsibilities of UNYOM concerned mainly, in addition to the cities of San'a and Al Hudaydah, the demilitarized zone on each side of the demarcated portion of the Saudi Arabia-Yemen border. It did not extend to the undefined portion of that border nor to the border between Yemen and the British-controlled South Arabian Federation.

From the very start, the Secretary-General pointed out that UNYOM, because of its limited size and function, could observe and report only certain indications of the implementation of the disengagement agreement. However, despite its shortcomings, the Mission did have a restraining influence on hostile activities in the area. The Secretary-General repeatedly expressed the view that the responsibility for implementing the agreement lay with Saudi Arabia and Egypt and progress could be best achieved through negotiations between them.

With this in view, he informed the Security Council that UNYOM could, within limits, serve as an intermediary and as an endorser of good faith on behalf of the parties concerned, and that it was his intention to have the Mission perform these roles to the maximum of its capability. When Mr. Spinelli was appointed Special Representative of the Secretary-General and head of UNYOM in November 1963, he devoted a great deal of his time and attention to good-offices efforts and held extensive discussions with officials of the three Governments concerned. These discussions were of an exploratory character to try to ascertain whether there were areas of agreement between the parties which might, through bilateral discussions or otherwise, lead to further progress towards disengagement and the achievement of a peaceful situation in Yemen.

Secretary-General's assessment

The assessment of the Secretary-General on the functioning of UNYOM and the implementation of the disengagement agreement, as set out in his successive periodic reports to the Security Council, are outlined below.

In his first report on this subject, dated 4 September 1963, the Secretary-General found no encouraging progress towards effective implementation of the agreement, although both parties had expressed a willingness to cooperate in good faith with UNYOM. He noted reluctance by each side to fulfil its undertakings regarding the agreement before the other side did so.

His second report of 28 October 1963, indicated limited progress. He stated that although the developments observed by UNYOM were far short of the disengagement and regularization of the situation which had been hoped for, they were in a limited way encouraging in that the scale of fighting had been reduced and conditions of temporary truce applied in many areas.

On 2 January 1964, he reported that UNYOM observations tended to confirm that, during the period under review, no military aid of significance had been provided to the royalists from Saudi Arabia, and that there had been a substantial net withdrawal of Egyptian troops from Yemen. Ground operations had further decreased in intensity. The Secretary-General reiterated his belief that the solution of the problem lay beyond the potential of UNYOM under its original mandate, and he referred to the extensive discussions his Special Representative had had with members of the three Governments concerned with a view to furthering progress towards disengagement and the achievement of a peaceful situation in Yemen.

A later report, submitted on 3 March 1964, raised a new problem: Yemeni and Egyptian sources asserted that large quantities of supplies were being sent to the royalists from the Bayhan area across the frontier with the South Arabian Federation. The Secretary-General pointed out in this connection that since that frontier was not included in the disengagement agreement, United Nations observers did not operate in that area. However, he mentioned that the nature and extent of the military operations carried out by the royalists during January and February would seem to indicate that arms and ammunition in appreciable amounts had been reaching them from that source.

The Secretary-General also reported that the royalists appeared to be well provided with money and to have engaged foreign experts to train and direct their forces, and that they had recently launched attacks against Egyptian troops. From the developments observed by UNYOM, he felt that progress towards the implementation of the disengagement agreement had been very disappointing during the period under review; a state of political and military stalemate existed inside the country, which was unlikely to be changed as long as external intervention in various forms continued from either side. On the other hand, he noted certain encouraging factors, particularly the increasing unity of feeling and purpose within the Arab world arising from a Conference of Arab Heads of State held in Cairo in mid-January 1964 and the resulting improvement in relations between Saudi Arabia and Egypt. The Secretary-General expressed the hope that the meeting to be held between the two parties in Saudi Arabia would result in some progress towards the implementation of the agreement and towards an understanding between the two Governments to cooperate in promoting political progress and stability in Yemen.

In his report dated 3 May 1964, the Secretary-General stated that there was no progress in troop reduction towards the implementation of the disengagement agreement and that no actual end of the fighting appeared to be in sight. He noted, however, that the two parties had reported noticeable progress in discussions of a number of problems at issue between them, and that a meeting between President Nasser of Egypt and Crown Prince Feisal of Saudi Arabia would be held in Cairo in the near future.

On 2 July, the Secretary-General reported that the military situation in Yemen had remained fairly quiet over the past two months, that no military aid by Saudi Arabia to the Yemeni royalists had been observed and that some slight progress in Egyptian troop reduction appeared to have occurred. Once again he appealed to the parties concerned to meet at the highest level with a view to achieving full and rapid implementation of the disengagement agreement.

Termination of UNYOM

In his final report dated 2 September 1964, the Secretary-General again acknowledged the failure of the parties to implement the disengagement agreement and the difficulties UNYOM faced in observing and reporting on these matters. There had been a substantial reduction in the strength of the Egyptian forces in Yemen but it seemed that the withdrawal was a reflection of the improvement in the situation of the Yemeni republican forces rather than the beginning of a phased withdrawal in the sense of the agreement. There were also indications that the Yemeni royalists had continued to receive military supplies from external sources. Noting that UNYOM had been able to observe only limited progress towards the implementation of the agreement, he reiterated his view that UNYOM's terms of reference were restricted to observation and reporting only, and that the responsibility for implementation lay with the two parties to the agreement. He stated that UNYOM had actually accomplished much more than could have been expected of it in the circumstances, and that during the 14 months of its presence in Yemen, the Mission had exercised an important restraining influence on hostile activities in the area.

On 4 September 1964, the activities of UNYOM ended and its personnel and equipment were withdrawn. Shortly after the withdrawal of UNYOM, relations between the parties steadily improved and issues were resolved between them. There has been no consideration of the matter in United Nations organs since the termination of that Mission.


© United Nations

Peace and Security
UN Home Page