Imagining a doomsday’s crisis with gleeful paranoia, “Steel Rain” unites a hyper-skilled North Korean operative with a nerdy presidential aide to stop a nuclear war. Adapting his own webtoon, South Korean writer-director Yang Woo-seok (“The Attorney”) whips up the sort of worst-case-scenario, anti-Communist hysteria that’s a hilarious throwback to the Cold War propaganda of 1970s […]