This is a battle of patience. The world puts tariffs against the US for everything. They have for decades. If you follow the world economy, treaties, UN and other global agency actions, the world HATES the US and feel we have too much wealth. They fines, tariff, bill, etc...the US for everything and they feel justified to do it.
The issue is, the US is now in debt over it to the sum of $36 trillion and growing. It needs to stop. Trump is over it and wants to break the cycle of this against the US. A tariff "war" is a game played to get other countries to reduce or eliminate their tariffs against the US. This will result in other countries buying more US goods...increasing revenue, GDP, etc...here in the US. It is also a play to get US companies to manufacture more here in the US to make the US more independent and create more jobs here in the US.
Will tariffs hurt the US...yes. In the short run. The world cannot come close to the US's GDP and ability to wait this out. Listening to Canada "thinking" they can hold their own in a trade war with the US is laughable. Most states in the US have a higher GDP than Canada as a whole. When was the last time you saw..."Made in Canada" on anything?
Pulling out of other organization like the WHO, World Economic associations, hopefully the UN and NATO, relieve the US of these financial burdens. The US pays billions into these and honestly, gets nothing back.
The other BIG issue on tariffs...Trump is wanting to use these in place of personal income taxes. If you can get rid of personal income taxes...I know for me that would be HUGE!!! I guarantee I would come out ahead as I don't buy that much but I pay through the nose on taxes. The offset would definitely be in my favor.
I could write all day on this. But hopefully this explains it.