Civil War, launched a successful peacekeeping mission in Namibia, and oversaw democratic elections in post-apartheid South Africa and post-Khmer Rouge Cambodia. In 1991, the UN authorized a US-led coalition that repulsed the Iraqi invasion of Kuwait. Brian Urquhart, under-secretary-general from 1971 to 1985, later described the hopes raised by these successes as a "false renaissance" for the organization, given the more troubled missions that followed. Beginning in the last decades of the Cold War, American and European critics of the UN condemned the organization for perceived mismanagement and corruption. In 1984, US President Ronald Reagan, withdrew his nation's funding from United Nations Educational, Scientific and Cultural Organization (UNESCO) over allegations of mismanagement, followed by the UK and Singapore. Boutros Boutros-Ghali, secretary-general from 1992 to 1996, initiated a reform of the Secretariat, reducing the size of the organization somewhat. His successor, Kofi Annan (1997–2006), initiated further management reforms in the face of threats from the US to withhold its UN dues. Though the UN Charter had been written primarily to prevent aggression by one nation against another, in the early 1990s the UN faced a number of simultaneous, serious crises within nations such as Somalia, Haiti, Mozambique, and the former Yugoslavia. The UN mission in Somalia was widely viewed as a failure after the US withdrawal following casualties in the Battle of Mogadishu. The UN mission to Bosnia faced "worldwide ridicule" for its indecisive and confused mission in the face of ethnic cleansing. In 1994, the UN Assistance Mission for Rwanda failed to intervene in the Rwandan genocide amid indecision in the Security Council. From the late 1990s to the early 2000s, international interventions authorized by the UN took a wider variety of forms. United Nations Security Council Resolution 1244 authorised the NATO-led Kosovo Force beginning in 1999. The UN mission (1999-2006) in the Sierra Leone Civil War was supplemented by a British military intervention. The invasion of Afghanistan in 2001 was overseen by NATO. In 2003, the United States invaded Iraq despite failing to pass a UN Security Council resolution for authorization, prompting a new round of questioning of the organization's effectiveness. Under the eighth secretary-general, Ban Ki-moon, the UN intervened with peacekeepers in crises such as the War in Darfur in Sudan and the Kivu conflict in the Democratic Republic of Congo and sent observers and chemical weapons inspectors to the Syrian Civil War. In 2013, an internal review