Robert Ludlum's The Treadstone Resurrection

Operation Treadstone has nearly ruined Adam Hayes. The top-secret CIA Black Ops program trained him to be an all but invincible assassin, but it also cost him his family and any chance at a normal life. Which is why he was determined to get out. Working as a carpenter in rural Washington state, Adam thinks he has left Treadstone in the past, until he receives a mysterious email from a former colleague, and soon after is attacked by an unknown hit team at his job site.