War on Terror Law and Legal Definition
The War on terror is an international military campaign launched in 2001 with the US and UK invasion of Afghanistan in response to the attacks on New York and Washington of 11 September 2001. It is a global military, political, legal and ideological struggle employed against organizations designated as terrorist and regimes that were accused of having a connection to terrorists or presented as posing a threat to the US and its allies in general. The phrase War on Terror was adopted by former US President George W. Bush and other high-ranking US officials. The campaign was led by the U.S. and the U.K. with the support of other North Atlantic Treaty Organization (NATO) and non-NATO countries. The campaign was originally carried on against al-Qaeda and other terrorist organizations with the purpose of eliminating them. It is also known as the Global War on Terror or the War on Terrorism.
When U.S. President Barack Obama took the office, the term war on terror was replaced with the term Overseas Contingency Operation. As a result the term war on terror was not used officially. However, it is still commonly used by politicians, in the media and officially by some aspects of government, such as the Army's Global War on Terrorism Service Medal.