"Typhoon" follows an intrepid naval officer tracking down a terrorist with a crazed need to destroy South Korea with Russian nuclear waste. But so much time is spent on the terrorist and his story, and he's so much a product of that divided peninsular culture, that you can't help but see beyond the simplicities of us and them. Suppose, it asks, it turns out that they are us?

Sin, as the terrorist is called, has a good reason to hate the South Koreans. He is by birth North Korean; 20 years earlier, when he was a child, his family plotted to reach the Austrian Embassy in Beijing, apply for amnesty and somehow get into South Korea.

However, while the Austrians were willing to be used as a conduit, political expediencies led Seoul to refuse entry; the defectors got massacred for their troubles. Only two survived: the young man who grew to be the terrorist, and his sister, who haunts "Typhoon" as a tragic, dying specter (she's played by Lee Mi Yeon).

Sin, far and away the most interesting character in the film, is played by Jang Dong Gun. The terror he brings cannot be righteous, but it is understandable and, in a certain weird light, impressive. He is pursued by a lean-jawed, straight-ahead hero type embodied by rugged Lee Jung Jae, who is as simple and straightforward as Jang is opaque and angry. It's a good match.

The director is Kwak Kyung Taek, who keeps things flying along but never quite goes nuts. A few others have compared this to a James Bond movie, but it's more of a Tom Clancy movie; it never leaves the real world that far behind, it has a fair sense of documentary reality, and the action sequences — from shootout to car chase to a commando takedown of a tanker on the high seas to a final knife fight — are extremely well managed.