The War on Terrorism (also referred to as the Global War on Terror, Global War on Terrorism, or Overseas Contingency Operation) is the common term for the military, political, legal and ideological conflict against what the effort's leaders describe as Islamic terrorism and Islamic militants, and was specifically used in reference to operations by the United States and its allies since the September 11, 2001 attacks.
The stated objectives of the war in the US are to protect US citizens and business interests in the US and abroad, break up terrorist cells in the US, and disrupt the activities of the international network of terrorist organizations made up of a number of groups under the umbrella of al-Qaeda.
Both the term and the policies it denotes have been a source of ongoing controversy, as critics argue it has been used to justify unilateral preemptive war, human rights abuses and other violations of international law. In March 2009, the Obama administration requested that Pentagon staff members avoid use of the term, instead using "Overseas Contingency Operation". The administration has re-focused US involvement in the conflict on the withdrawal of its troops from Iraq, the closing of Guantanamo Bay detention camp, and increasing the number of troops in Afghanistan
Led by Osama Bin Laden, a radical Islamist trained by the US during the 1980s to conduct guerilla attacks against the Soviet Army in Afghanistan , Al-Qaeda formed a large base of operations in Afghanistan, which had been ruled by the Islamist extremist regime of the Taliban since 1996.
Following the bombings in Kenya and Tanzania, U.S. President Bill Clinton launched Operation Infinite Reach, a bombing campaign in Sudan and Afghanistan against targets the US asserted were associated with al-Qaeda. Although others have questioned the Sudan plant's use as a chemical warfare plant  The strikes failed to kill al-Qaeda'a leaders or their Taliban supporters (targets included a civilian pharmaceutical plant in Sudan that produced much of the region's malaria drugs and around 50% of Sudan's pharmaceutical needs ).
Next came the 2000 millennium attack plots which included an attempted bombing of Los Angeles International Airport. In October 2000 the USS Cole bombing occurred, followed in 2001 by the September 11 attacks.
By 2003, 12 major conventions and protocols were designed to combat terrorism. These were as well, adopted and ratified by a number of states to become international law. These conventions require states to co-operate on principal issues regarding unlawful seisure of aircraft for example, the physical protection of nuclear materials and freezing assets of militant networks. 
In 2005 the Security Council also adopted resolution 1624 concerning incitement to commit acts of terrorism and the obligations of countries to comply with international human rights laws. Although both resolutions require mandatory annual reports on counterterrorism activities by adopting nations, the United States and Israel have both declined to submit reports.