The Mordida Man by Ross Thomas

A freelance fixer comes out of retirement to rescue the President's kidnapped brother

American agents abduct a high-profile terrorist in broad daylight on the streets of London, subduing him with a tranquilizer. He dies a few hours later on a flight back to Washington, DC, and the body is dropped into the ocean. Hours later, the President's brother-a political powerhouse in his own right-boards a plane to Las Vegas that doesn't land in Nevada. Libyan radicals are at the controls, and he is their prisoner.

The only man who can save him is Chubb Dunjee. A former United Nations operative with skills in every aspect of political negotiation, Chubb became famous for solving problems with well-placed bribes. Saving the President's brother should be no trouble for him. But the Libyans don't want a bribe. They want blood.