The other U.S. trade problem that you might not know about

Open this photo in gallery: Chinese national flags flutter near shipping containers at the Yangshan Port outside Shanghai, China, Feb. 7.Go Nakamura/Reuters Louis Martel is president and chief executive officer of Canada Steamship Lines Group. The United States has a long history of implementing protectionist trade policies, often realizing in hindsight that such measures ultimately hurt Americans. The latest example is the tariffs that took effect against Canada and Mexico this week. But there is another measure that has been getting less attention: the U.S. President Donald Trump administration's proposal to impose exorbitant port fees on Chinese-built vessels that dock…