Terrorism is today one of the most serious and visible threats to security of mankind and all efforts of the United Nations (UN) to curb the threat has been anything but successful. Since September 11, 2001 terrorists attack on the United States (US), the United Nations adopted strong measures aimed at reducing the activities of terrorists. However, from 2001 till date, several major terrorists attacks in some parts of the world, has been carried out successfully. This book examines the phenomenon of terrorism and the roles of the United Nations and its agencies in the global war on terrorism.