Kites fly high over San Francisco and Kabul, but not much else soars in Marc Forster’s flaccid adaptation of Khaled Hosseini’s vivid 2002 novel, which covers three decades of Afghanistan’s misery. The novel spins a potboiling tale of betrayal, cowardice, and making amends, but Forster, armed with a capably hands-off screenplay by David Benioff, has made a drama as bland and beige as its tasteful palette, whose pacing wouldn’t look out of place in the Sunday night slot on PBS. Amir, an expatriate Afghani writer with a dark secret, is played with dour lack of expression by Egyptian-born actor Khalid Abdalla, and the movie wakes only slightly on its trips back to Kabul, where the close friendship between two motherless boys withers on the vine due to jealousy, a dark secret, and a predatory act of child exploitation. You can’t fault Forster’s efforts to honor his subject, but the care he has taken to respect local culture drains even the final act, when Amir returns to Kabul to atone for his sins and gets beaten within an inch of his life, of the novel’s propulsive momentum.