This week President Trump proposed taxing steel and aluminum imported into the U.S. through the use of a tariff. While tariffs have been used a various times by the U.S. government, they can lead to a declining economic value for all as foreign governments look to retaliate through the use of their own tariffs.
For a humorous history lesson of what happens when the use of tariffs go awry watch this clip Lesson on Tariffs from Ferris Bueller's Day Off