A Devil is Waiting by Jack Higgins (Used)

The Danger is Clear

]On the day the US President is entertained by the British Prime Minister, a fanatical mullah accuses the President of war crimes, offering eternal paradise to anyone who will assassinates him. It is an open call to rain blood and fire on the streets of London. And it's about to be answered. 

The Threat is Real 

Sean Dillon, General Ferguson and Daniel Holley are rushed into action to combat a huge upsurge in terrorism, helped by extraordinary new recruit, Intelligence Corps Captain and Afghan war hero, Sara Gideon.

A Devil is Waiting 

With enemies on all sides, they discover that, though bin Laden may be gone, the threat remains as terrible as ever - and the assassination plot is only the beginning...