Tommy Lee Jones pontificates and poses with hands on hips as General Douglas MacArthur during his scant screen time in Emperor, vainly trying to muster up a showy performance that might save this historical drama from drowning in torpor. He cannot, alas, given that Peter Webber’s film spends so much of its energy detailing the efforts of General Bonner Fellers (Matthew Fox) to investigate, at the conclusion of World War II, whether Japan’s Emperor Hirohito was responsible for Pearl Harbor, and should thus be tried and hanged for war crimes. Given its true-life basis, the story is already devoid of suspense regarding Hirohito’s ultimate fate, and Fellers’s inquiry is made more sluggish by dramatically inert conversations with Japanese officials who don’t realize that their lack of cooperation will doom their beloved emperor to the gallows. Their desire to praise the values of Japanese culture—honor, loyalty, devotion—is shared by the film. Amid the ham-fisted moral equivalency, Webber indulges in flashbacks to Fellers’s ill-fated romance with a Japanese beauty (Eriko Hatsune). Those sequences are a clunky means of conflating the personal and political, and are ultimately low-lighted by abjectly corny scenes of Fox and Hatsune slo-mo frolicking in a sun-dappled bamboo forest.