Now Wait For Last Year by Philip K. Dick
First, Gino Molinari was assassinated by a political Rival. Then he died of a heart attack. But now he is back, younger and more vigorous than ever, giving Earth new hope of survival in the war against the alien reegs. But is this really Molinari, or a robant masquerading as Earth?s overlord? Whatever the truth, only he can save the Solar System ? if he can stay alive long enough, or at least not stay dead for too long.