You should do some research on the issue of Canadian lumber and US tariffs.
Last week, the extraordinary challenge panel dismissed Washington's claims that Canadian softwood exports are subsidized and damage the U.S. lumber industry. Canada immediately called on Washington to return about $5 billion collected from Canadian companies. The Americans refused, saying the ruling didn't end the matter because it did not deal with a 2004 decision from the U.S. International Trade Commission which supported the American case.