Zwick made his name in TV and film with contempo dramedies like “thirtysomething,” only to switch to a much larger canvas at the end of the 1980s with his Civil War epic “Glory.” Since then, he’s remained fascinated with the big picture, whether it be “Legends of the Fall,” “The Last Samurai” or this year’s “Blood Diamond.”

“I’ve been interested in what is epic in very personal stories and what is personal in epic stories,” he says. “I’m not sure they are mutually exclusive.”

Set in 1995 during the civil war in Sierra Leone, “Blood Diamond” focuses on forced labor camps and the recruitment of children by rebel armies. But Zwick doesn’t call it a message movie.

“The film has to work in terms of a personal story, which must be its most passionate focus,” he says. “That’s why people go to the movies. You invest in relationships and the journeys of characters. The politics, as such, resonate outward.”

Zwick says the pic’s African shoot was challenging. “We were in Mozambique and saw the remnants of civil war in one of the most impoverished places on Earth. Trying to keep our own objectivity and detachment in the middle of something like that is very upsetting.”