Among the trophies of a war between Singapore and Hong Kong: an ancient Chinese imperial throne worth US$11 million which set an auction record in Hong Kong recently. Longtime rivals in trade and finance, Hong Kong and Singapore are vying to become Asia's regional arts hub, part of a strategy to be crowned Asia's top city. Already the third-largest art-auction market in the world, Hong Kong has set aside nearly US$3 billion for a massive development known as West Kowloon Cultural District...