The justification for these tariffs have changed every few fucking minutes.
On paper, the excuse for him to enact these blanket tariffs is "national security", then it became a negotiating tactic to combat of Fentanyl smuggling and illegal Canadian immigrants, then it was about bringing manufacturing back to America, then it was about evening out supposed "trading imbalances", then it was about owning China (245% fucking increase on goods), then it was about forcing countries into new trade deals, then it was about Fentanyl, then it was about manufacturing, etc etc etc
Bottom line is that this tariff bullshit is Trump's only method of governance. The courts cucked him out of building the wall and doing a large amount of what he campaigned on back in his first term, but they turned a blind eye to tariffs which allowed him to decimate the farming industry via his first trade war with China (which your tax dollars bailed them out of!).
Tariffs are the singular hammer he has to try and smack down any perceived nail which is why he'll gladly shoot the economy in the dick if it means he gets to try and exert power on the global stage (outside of carrying Netanyahu's orders here and there).