Hammarskjöld's activities in the political field were more numerous and far-reaching than Lie's had been. Both the General Assembly and the Security Council repeatedly relied on his initiative and advice and entrusted important tasks to him.
The 1954 General Assembly set a precedent when it asked the secretary-general to seek the release of 11 US fliers held prisoner by mainland China. The Assembly resolution left the course of action entirely to his judgment. After various preparations, Hammarskjöld flew to Peking (now Beijing) for personal negotiations with that government, and the 11 fliers were released. This success greatly increased the readiness of the Assembly to rely on the secretary-general as a troubleshooter.
The Suez Crisis. Grave responsibilities were entrusted to the secretary-general by the General Assembly in connection with the establishment and operation of the UN Emergency Force (UNEF). On 4 November 1956, at the height of the crisis resulting from British, French, and Israeli intervention in Egypt, the secretary-general was requested to submit a plan within 48 hours for the establishment of a force "to secure and supervise the cessation of hostilities." The Assembly approved his plan and, at his suggestion, appointed Major-General E. L. M. Burns, Chief of Staff of the UN Truce Supervision Organization, as the chief of UNEF. The Assembly authorized the secretary-general to take appropriate measures to carry out his plan, and an advisory committee of seven UN members was appointed to assist him. Hammarskjöld flew to Egypt to arrange for the Egyptian government's consent for UNEF to be stationed and to operate in Egyptian territory. He was given the task of arranging with Egypt, France, Israel, and the United Kingdom the implementation of the cease-fire and an end to the dispatch of troops and arms into the area and was authorized to issue regulations and instructions for the effective functioning of UNEF.
Hammarskjöld's Views on Developing the Role of Secretary-General. Even before the Middle East crisis of 1956, Hammarskjöld had pointed to the need for the secretary-general to assume a new role in world affairs. On his reelection to a second term, Hammarskjöld told the General Assembly that he considered it to be the duty of the secretary-general, guided by the Charter and by the decisions of the main UN organs, to use his office and the machinery of the organization to the full extent permitted by practical circumstances. But he then declared: "I believe it is in keeping with the philosophy of the Charter that the secretary-general be expected to act also without such guidance, should this appear to him necessary in order to help in filling a vacuum that may appear in the systems which the Charter and traditional diplomacy provide for the safeguarding of peace and security." (Italics added.) In other words, inaction or a stalemate either at the UN or outside of it may be justification for the secretary-general to act on his own.
Thus, in 1958, Hammarskjöld took an active hand in the Jordan-Lebanon crisis. After a resolution for stronger UN action failed to carry in the Security Council, he announced that he would nevertheless strengthen UN action in Lebanon and "accept the consequences" if members of the Security Council were to disapprove; none did. In the fall of 1959, the USSR made it known that it did not favor a visit by the secretary-general to Laos and, in particular, the assignment of a special temporary "UN ambassador" there. Yet Hammarskjöld did go to Laos to orient himself on the situation in that corner of Southeast Asia, and he assigned a high UN official as the head of a special mission to Laos. In March 1959, Hammarskjöld sent a special representative to help Thailand and Cambodia settle a border dispute. He acted at their invitation without specific authorization by the Security Council or the General Assembly. The dispute was settled.
In his report to the 1959 Assembly, he said: "The main significance of the evolution of the Office of the Secretary-General … lies in the fact that it has provided means for smooth and fast action … of special value in situations in which prior public debate on a proposed course of action might increase the difficulties … or in which … members may prove hesitant…."
The Congo Crisis. By far the greatest responsibilities Hammarskjöld had to shoulder were in connection with the UN Operation in the Congo (now Zaire).
On 12 and 13 July 1960, respectively, President Joseph Kasavubu and Premier Patrice Lumumba of the newly independent Congo each cabled the secretary-general, asking for UN military assistance because of the arrival of Belgian troops and the impending secession of Katanga. At Hammarskjöld's request, the Security Council met on the night of 13 July. He gave his full support to the Congo's appeal and recommended that the Council authorize him to "take the necessary steps" to set up a UN military assistance force for the Congo, in consultation with the Congolese government and on the basis of the experience gained in connection with the UNEF in the Middle East. The Security Council so decided.
Since the Congo operation thus initiated was of much greater dimensions than the UNEF operation, the responsibilities imposed upon the secretary-general were correspondingly heavier, for, although the Security Council and the General Assembly guided Hammarskjöld, he himself had to make extraordinarily difficult decisions almost daily, often on highly explosive matters that arose as a result of serious rifts within the Congolese government and many other factors.
Various member governments, including the USSR and certain African and Western countries, criticized Hammarskjöld for some actions that the UN took or failed to take in the Congo. At times, he had to face the possibility that some country that had contributed military contingents to the UN force would withdraw them.
When it became known in February 1961 that Lumumba, who had been deposed by Kasavubu early in September 1960 and later detained by the Léopoldville authorities, had been handed over by them to the Katanga authorities and subsequently murdered, Hammarskjöld declared that the UN was not to blame for the "revolting crime." However, several delegates claimed that he should have taken stronger measures to protect Lumumba.
The " Troika " Proposal. The USSR had asked for Hammarskjöld's dismissal long before the assassination of Lumumba. Premier Khrushchev, as head of the Soviet delegation to the 1960 General Assembly, accused Hammarskjöld of lacking impartiality and of violating instructions of the Security Council in his conduct of the UN operation in the Congo. He also proposed a basic change in the very institution of the secretary-general, arguing that since the secretary-general had become "the interpreter and executor of decisions of the General Assembly and the Security Council," this one-man office should be replaced by a "collective executive organ consisting of three persons, each of whom would represent a certain group of states"—namely, the West, the socialist states, and the neutralist countries; the institution of a "troika," he declared, would guarantee that the UN executive organ would not act to the detriment of any of these groups of states.
Hammarskjöld rejected the accusations against his impartiality, declared that he would not resign unless the member states for which the organization was of decisive importance or the uncommitted nations wished him to do so, and received an ovation from the overwhelming majority of the delegations. He also stated that to replace the one-man secretary-general by a three-man body would greatly alter the character and limit the scope of the UN.
Outside the Soviet bloc there had been little support for the "troika" proposal, but some "subtroika" proposals were advanced. Hammarskjöld in turn suggested that his five top aides, including a US and a Soviet citizen, advise the secretary-general on political problems. Discussions of the question were interrupted by his death.
Death of Dag Hammarskjöld. Because of dangerous developments in the Congo, Hammarskjöld flew there in September 1961. On the night of 17 September, the plane carrying him from Léopoldville to a meeting with the Katanga secessionist leader at Ndola, Northern Rhodesia, crashed in a wooded area about 16 km (10 mi) west of Ndola airport. Hammarskjöld and all 15 UN civilian and military personnel traveling with him, including the crew, were killed. The exact cause of the tragedy has not been determined. An investigation commission appointed by the General Assembly reported several possibilities: inadequate technical and security preparations for the flight, an attack on the plane from the air or the ground, sabotage, or human failure by the pilot.