nel2lar, ... There are many possible reasons for the tariffs ...
FYI: The officially stated rational for the steel and aluminum tariffs is not about economics, but national security. In order to build the weapons of war these raw materials are required. Therefore for national security interests, each power (country) must have the ability to make these raw materials.
The US steel manufacturers have been in a fifty year decline due to many varying factors such as environmental regulations, labor (union) costs, bad management, foreign competition, etc.
Of these listed factors, the federal government can only really control one, foreign competition, with either tariffs or corporate welfare. (Forget about management, i.e. nationalizing the steel and aluminum mills would be disastrous) Only one of these, tariffs, doesn't impact the spending deficit. The result is the same, higher prices for steel and aluminum. So the Trump administration went with the tariffs.
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Now it doesn't matter if you agree with this assessment or not. It doesn't matter if you think the reason for the tariffs is hogwash or not. I'm just stating the US government's position for the tariffs so we have a baseline in this discussion.
...Ved.