Who is David Stark from Dragon Bones: A Novel and what is their importance?

David Stark is the American lawyer, who is married to Liu Hulan. He is known in China for his ability to handle delicate matters for the government, as well as for political and business figures in a way that preserves the dignity of the government. David loves Hulan dearly, but when their child dies, he feels she pushes him away due to her own guilt. David is hired by the State Cultural Relics Bureau to investigate the theft of relics from Site 518. David's character represents admired foreign interest in China. David would normally be under scrutiny, but because of his wife, he is instead used as an asset to the country. He is described as cautious.