As the 10th anniversary of Princess Diana's death approaches, a new book takes another look at a long-dismissed claim that Prince Harry's father was actually Diana's lover, James Hewitt. American writer Christopher Andersen, author of After Diana: William, Harry, Charles and the Royal House of Windsor (out today, Hyperion, $25.95), also says Harry eventually will serve in Afghanistan — as a kind of compensation for not being allowed to serve with his Army regiment in Iraq. "I think they'll wait until the interest dies down," he says, "and then they'll get him (to Afghanistan) and back before anyone knows it."