Daily Mail, 23 January 2010
Fears of a terrorist attack on Hillary Clinton when she is in Britain next week prompted the UK terror threat level to be raised, according to a leading expert.
Professor Richard Bonney believes the arrival of the U.S. Secretary of State in London next week is why the official level has gone from substantial to severe.
Home Secretary Alan Johnson announced the shift last night. The new level denotes that an attack is 'highly likely' and is the second highest on a five-step scale.
Mrs Clinton and other leading foreign ministers are due in London this Wednesday and Thursday for two major summits on Afghanistan and Yemen.

..to commit a terrorist attack on a terrorist?