the start of the Somali civil war in 1988 and the fall of the Siad Barre regime in January 1991, the UN missed at least three opportunities to prevent major human tragedies; when the UN tried to provide humanitarian assistance, they were totally outperformed by NGOs, whose competence and dedication sharply contrasted with the UN's excessive caution and bureaucratic inefficiencies. Sahnoun warned that if radical reform were not undertaken, then the UN would continue to respond to such crises with inept improvisation. Beyond specific instances or areas of alleged ineffectiveness, some scholars debate the overall effectiveness of the UN. Adherents to the realist school of international relations take a pessimistic position, arguing that the UN is not an effective organization because it is dominated and constrained by great powers. Liberal scholars counter that it is an effective organization because it has proved capable of solving many problems by working around the restrictions imposed by powerful member states. The UN is generally considered by scholars to be more effective in realms such as public health, humanitarian assistance, and conflict resolution. Inefficiency and corruption Critics have also accused the UN of bureaucratic inefficiency, waste, and corruption. In 1976, the General Assembly established the Joint Inspection Unit to seek out inefficiencies within the UN system. During the 1990s, the US withheld dues citing inefficiency and only started repayment on the condition that a major reforms initiative be introduced. In 1994, the Office of Internal Oversight Services (OIOS) was established by the General Assembly to serve as an efficiency watchdog. In 2004, the UN faced accusations that its recently ended Oil-for-Food Programme—in which Iraq had been allowed to trade oil for basic needs to relieve the pressure of sanctions—had suffered from widespread corruption, including billions of dollars of kickbacks. An independent inquiry created by the UN found that many of its officials had been involved in the scheme, and raised "significant" questions about the role of Kojo Annan, the son of Kofi Annan. Model United Nations The United Nations has inspired the extracurricular activity Model United Nations (MUN). MUN is a simulation of United Nations activity based on the UN agenda and following UN procedure. It is usually attended by high school and university students who organize conferences to simulate the various UN committees to discuss important issues of the day. Today, MUN educates tens of thousands on the activities of the UN around