In 2002 Belgium officially apologised for its role in the assassination of Lumumba; the CIA has long been speculated of complicity, as they had seen Lumumba's politics were too far left. The Soviet Union during the Cold War years was active in expanding its influence in Africa against European powers, giving ‘anti-colonialism’ as a rationale for the increase of its power in the region. A series of rebellions and separatist movements seemed to shatter the dream of a unitary Congolese state at its birth. Although the nation was independent, Belgian paratroopers intervened in the Congo on various occasions to protect and evacuate Belgian and international citizens. The United Nations maintained a large peace-keeping operation in the Congo from late 1960 onward. The situation did not stabilise until 1964–65. Katanga province was re-absorbed and the so-called Simba Rebellion ended in Stanleyville (province Orientale). Shortly after that army colonel Joseph Désiré Mobutu ended the political impasse by seizing power in a "coup d'état".