Without Fail (Jack Reacher 6) by Lee Child

Skilled, cautious, and anonymous, Jack Reacher is perfect for the job: to assassinate the vice president of the United States. Theoretically, of course. A female Secret Service agent wants Reacher to find the holes in her system, and fast--because a covert group already has the vice president in their sights. They've planned well. There's just one thing they didn't plan on: Reacher.