Decline of the phrase's usage by the US government

In April 2007, the British government announced publicly that it was abandoning the phrase "war on terror" because it found it less than helpful. This was explained later by Lady Eliza Manningham-Buller. In her 2011 Reith lecture, the former head of MI5 said that the 9/11 attacks were "a crime, not an act of war. So I never felt it helpful to refer to a war on terror."