Clint Eastwood plays a Secret Service agentactually Dirty Harry in disguise (with minor variations)emotionally devastated by the assassination of John F. Kennedy, who gets a shot at redeeming himself 30 years later when a loony assassin (John Malkovich) also trained by the Secret Service menaces the president and baits Eastwood about it, for no discernible reason except to keep Eastwood working. If you don’t care about such motivations, this is a pretty good thriller, though not one you’re likely to remember for very long. Wolfgang Petersen (Das Boot) directed from a script by Jeff Maguire; with Rene Russo. (JR)