The long-threatened tariff-battle between the U.S. and China takes on a tangible form on July 6 with the application of duties on $34 billion of products by both countries. America’s list is driven by its concerns about Chinese industrial development and so focuses on PC components ($1.4 billion) and capital goods (e.g. $869 million of fuel pumps) as well as cars ($1.6 billion). China is more focused on retaliation and so is targeting American cars ($10 billion) as well as soybeans ($11 billion) among a wide range of other agricultural produce. There are at least three more stages in the...