The escalating trade dispute between the U.S. and China could hinder a global boom in petrochemicals production largely centered on cheap natural gas liquids from American shale fields, according to an analysis by IHS Markit. Both countries have proposed tariffs on billions of dollars' worth of imports, including certain chemicals and plastics. IHS Markit anticipates that the measures, if implemented, would deal a blow to U.S. producers of polyethylene, propane and vinyls and force them to search for export opportunities in other Asian countries. The back-and-forth began last month, when the Trump Administration imposed tariffs on Chinese steel and aluminum.