A discomforting topic in an obtuse format unfocused on any single character for long, punctuated with ambiguous outcomes, seems a formula for frustration; and yet Kathryn Bigelow imprints her signature hyperrealism with panache onto a fictional but not far-fetched situation, and the result – A House of Dynamite (B+) – is an intense, often riveting political think piece. Instead of a straight-up doomsday clock thriller, it is divided into three acts depicting the same critical moments of escalating activity as an unattributed nuclear missile careens toward the American homeland. The only edge-of-your-seat part is the first act from the White House situation room POV featuring an effective Rebecca Ferguson, who pulls viewers directly into the propulsive real-time plot. The remaining acts center on less interesting characters, a gruff general and an early-term commander-in-chief, embodied well by Tracy Letts and Idris Elba, respectively. These second and third parts pull back the microscope and introduce different degrees of decision making into the narrative, allowing viewers multiple portals for determining how they would react if faced with a similar scenario. These acts of subsequent diminishing intensity admittedly  let some air out of the story momentum but not out of the argument against mutually-assured annihilation. Bigelow peppers in matter-of-fact moments of daily life to heighten the realism and emotion, which is helpful except in at least one location laden with heavy-handed symbolism. Viewers can’t help but confront the nuclear issue and how one would respond after viewing many competent and well-trained characters struggle under the spotlight of real impending terror. Noah Oppenheim’s script offers no easy answers. Volker Bertelmann’s stirring score is a standout feature. In total it’s a flawed but vital conversation-starter movie.