United Nations General Assembly (UNGA) resolution 377 A, the "Uniting for Peace" resolution, states that in any cases where the Security Council, because of a lack of unanimity amongst its five permanent members, fails to act as required to maintain international peace and security, the General Assembly shall consider the matter immediately and may issue any recommendations it deems necessary in order to restore international peace and security. If not in session at the time the General Assembly may meet using the mechanism of the emergency special session.
The Uniting for Peace resolution—also known as the "Acheson Plan"—was adopted 3 November 1950, after fourteen days of Assembly discussions, by a vote of 52 to 5 (Czechoslovakia, Poland, the Ukrainian Soviet Socialist Republic, the Union of Soviet Socialist Republics and the Byelorussian Soviet Socialist Republic), with 2 abstentions (India and Argentina).
In it, the General Assembly:
"Reaffirming the importance of the exercise by the Security Council of its primary responsibility for the maintenance of international peace and security, and the duty of the permanent members to seek unanimity and to exercise restraint in the use of the veto," ...
"Recognizing in particular that such failure does not deprive the General Assembly of its rights or relieve it of its responsibilities under the Charter in regard to the maintenance of international peace and security," ...
"Resolves that if the Security Council, because of lack of unanimity of the permanent members, fails to exercise its primary responsibility for the maintenance of international peace and security in any case where there appears to be a threat to the peace, breach of the peace, or act of aggression, the General Assembly shall consider the matter immediately with a view to making appropriate recommendations to Members for collective measures, including in the case of a breach of the peace or act of aggression the use of armed force when necessary, to maintain or restore international peace and security."
To facilitate prompt action by the General Assembly in the case of a dead-locked Security Council, the resolution created the mechanism of the "emergency special session" (ESS), which can be called upon the basis of either a procedural vote in the Security Council, or within twenty-four hours of a request by a majority of UN Members being received by the Secretary-General. In procedural votes, the permanent members of the Security Council—the so-called "P5"—do not have the ability to block the adoption of draft resolutions, so unlike substantive matters, such resolutions can be adopted without their consent.
Emergency special sessions have been convened under this procedure on ten occasions, with the most recent convened in 1997. However, unlike preceding ESSs, the tenth ESS has been 'adjourned' and 'resumed' on numerous occasions, over the past several years, and remains adjourned. Indeed, more than ten separate 'meetings' have been held by the Assembly, whilst sitting in tenth ESS, since 2000.
While the "emergency special session" framework was established by resolution A/RES/377 A, the UN Charter always contained provisions for "special sessions", which, according to the General Assembly's current "Rules of Procedure", can be called within fifteen days of a request being received by the Secretary-General.
On 3 November 1950, the General Assembly adopted resolution 377 A (V), which was given the title “Uniting for Peace”. The adoption of this resolution came as a response to the strategy of the Union of Soviet Socialist Republics (USSR) to block any determination by the Security Council on measures to be taken in order to protect the Republic of Korea against the aggression launched against it by military forces from North Korea. At the initial stage of this armed conflict, in June 1950, the Security Council had been able to recommend to the Members of the United Nations to “furnish such assistance to the Republic of Korea as may be necessary to repel the armed attack and to restore international peace and security in the area” (resolution 83 (1950) of 27 June 1950). The resolution could be passed because the USSR, at that time, boycotted the meetings of the Security Council with the aim of obtaining the allocation of the permanent Chinese seat to the communist Government in Beijing. It assumed that in its absence the Security Council would not be able to discharge its functions since Article 27, paragraph 3, of the Charter provides that substantive resolutions of the Security Council require an affirmative vote of nine members “including the concurring votes of the permanent members”. The majority of the members of the Security Council, however, were of the view that absence from the meeting room could not prevent the key organ of the United Nations from acting validly, a view that was later endorsed by the International Court of Justice (ICJ) (Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) notwithstanding Security Council Resolution 276 (1970), Advisory Opinion, I.C.J Reports 1971, p. 16, at para. 22). Given that its protests remained fruitless, the USSR sent again, as from August 1950, a delegation to the meetings of the Council which cast a negative vote on a United States draft resolution condemning the continued defiance of the United Nations by the North Korean authorities. In order to overcome this impasse, the United States, under the leadership of its Foreign Secretary Dean Acheson, succeeded in persuading the General Assembly that it should claim for itself a subsidiary responsibility with regard to international peace and security, as enunciated by Article 14 of the Charter. The result of these efforts was resolution 377 A (V).