Civil wars lend themselves to epic storytelling on the scale of “Gone With the Wind.”

Such is the case with the Nigerian war of the late 1960s, which divided a country at the same time it inspired a gifted writer, Chimamanda Ngozi Adichie, to create a 2006 best-seller with the expressive title, “Half of a Yellow Sun.”

Unfortunately, in Biyi Bandele’s choppy new film adaptation of Adiche’s 542-page novel, the sexual relationships overpower the politics. The sometimes sudsy drama occasionally recalls the campiness of “White Mischief.” Like many a lengthy novel, it might have worked better as a television series.

Thandie Newton and Chiwetel Ejiofor do generate some sparks as a couple who can’t get enough of each other as the country dramatically falls apart. As a radical professor, Ejjofor brings passion and intelligence to his role.

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As his easily distracted mistress, condemned by the professor’s troubled mother as “a witch,” Newton never fails to engage.

They’re observed by a mostly mute houseboy who acts as the story’s conscience. If the filmmakers had taken a more balanced approach to emphasizing his viewpoint, the picture might have been more compelling.

But the street confrontations are effectively staged — and timely. Nigeria has been in the news lately, and Bandele’s film is at its best when it suggests immediacy.

John Hartl: