Al-Qaeda (also al-Qaida, al-Qa'ida, or al-Qa'idah and meaning The Base) is an international alliance of Sunni Salafist terrorist organizations founded on August 11, 1988 by Osama bin Laden and other veterans of the Soviet–Afghan War. Al-Qaeda is responsible or claimed to be responsible for numerous terrorist attcks in many countries, the most notorious being the September 11, 2001 attacks that occurred in New York City and Northern Virginia. These attacks were followed by the U.S. government launching the campaign known as the War on Terror.
The group has been defined as "a radical Sunni Muslim umbrella organization established to recruit young Muslims into the Afghani mujahideen and would be aimed to establish Islamist states throughout the world, overthrow ‘un-Islamic regimes’, expel U.S. soldiers and Western influence from the Gulf, and capture Jerusalem as a Muslim city," by the United States Department of Defense. The alleged objectives of Al-Qaeda include the end of foreign influence in Muslim countries and the creation of a new Islamic caliphate. Reported beliefs include that a Christian-Jewish alliance is conspiring to destroy Islam, and that in jihad the killing of bystanders and civilians is Islamically justified. Its management philosophy has been described as "centralization of decision and decentralization of execution."
Characteristic terror techniques allegations include use of suicide attacks and simultaneous bombings of different targets. Activities ascribed to it may involve members of the organization, who have taken a pledge of loyalty to bin Laden, or the much more numerous "Al-Qaeda-linked" individuals who have undergone training in one of its camps but not taken any pledge. Following 9/11 and the launching of the war on terror, it is thought al-Qaeda's leadership has "become geographically isolated", leading to the "emergence of decentralized leadership" of regional groups using the al-Qaeda brand name.