As soon as a Uyghur athlete helped light the Olympic flame at the Beijing Olympics, the debate began: Was it a defiant signal from Chinese leaders, or proof that protests around the world were having impact? The selection of Dinigeer Yilamujiang for the supreme honor of being a final Olympic torchbearer at the ceremony that opened the Winter Games in Beijing on Friday night was a huge surprise. What it meant — because Olympic gestures like this always have meaning — wasn’t clear. U.S.-based human rights lawyer Rayhan Asat — whose brother Ekpar Asat is among more than 1 million...