I can understand that the US government wants to achieve a better trade balance, and reduce the national debt. The US government has been trying to achieve that for decades already. But the way they are trying to do that now seems way too crude.
Like, raising a 25% tarrif on cars imported from Germany, Japan and China may be a good idea.
The auto industries of Germany, Japan and China wouldn’t be happy about that because their sales to the US would drop, but at least it would be advantageous for the US auto industry when imported cars become much more expensive.
But by also raising 25% tarrifs on steel and aluminium and many other things that the US auto industry needs to import to be able to produce cars, US cars also become much more expensive, negating much of the advantage I mentioned above.
Also, the general uncertainty surrounding those tariffs (switching them on and off seemingly at random) means that the US auto industry is not building new factories and hire workers any time soon, gambling on a potential increased demand that may never come.
So what happens in the shorter term is that cars will become much more expensive in the US.
People will probably delay replacing their cars for the time being because they can’t afford a new one. So I predict US car sales figures will drop, causing layoffs in the auto industry in the US and possibly also in Germany, Japan and China.
Now, this would reduce the US trade deficit, but it would also worsen the US economy. This may not work out well for the national debt, as having a worse overall economy means less tax revenues, and they may even end up having to bailout the US auto industry again (like the $80 billion bailout in 2008-2010).