In the obvious shorthand, Flame and Citron is Black Book meets Munich. Like Steven Spielberg’s Munich, it’s a sober thriller about how political assassins occupy uneasy moral ground, especially when they’re driven by a lust for vengeance. And, like Paul Verhoeven’s Black Book, it’s a World War II thriller about sex and betrayal and how hard it is to trust anyone in occupied territory. I think I prefer both of those movies to this one, but Flame and Citron has its own muscles to flex. In its cool, detached regard for the predicament its protagonists find themselves in, it’s probably tougher than either of them.