Refers specifically to the U.S.-led global military campaign against terrorism that began after the September 11 attacks in 2001.
See also: 反テロ戦争
The War on Terror began in 2001.
The effects of the War on Terror spread across the world.
Compound of 対 (たい, 'against'), テロ (abbreviation of テロリズム, 'terrorism'), and 戦争 (せんそう, 'war'). A direct translation of the English term 'War on Terror'.