If he doesn't think it will affect him personally, he doesn't care what happens.

We live in a well-informed bubble, but most 'muricans still believe that he's showing the world how to be a strong nation by punishing their bad behavior with tariffs. Midterm elections are coming up, so he needs to up the ante (esp. since the Iran war doesn't really make him look good).

In other words: (short term) votes are more important than (long term) effects of his "policies".

Imagine a large sandbox where children play together. Then one big bully and his cronies show up to stomp all the sand castles and confiscate the shovels and buckets, saying his dad owns the playground. If a kid gives him a nickel, the kid gets the tools back. Nobody has a good time. Kids stop showing up. They meet somewhere else now. Everyone hates that bully. The bully doesn‘t care because he got a few nickels out of burning these bridges.

Trump is a playground bully who uses his position to bully people into making him gifts. And he probably thinks he‘s very clever doing that. He is perfectly aware his actions are destroying trillions of dollars in economic damages but the occasional bribe here and deal there have made him a billionaire. For all he cares the USA can burn to the ground along with the rest of the world. He‘s getting his bag like the criminal he is.

Yes

To a large extend this is just stock market manipulation for him and his buddies to profit from.

He already has. It takes a few years for these changes to play out. When the shit hits the fan, Americans will vote for the other guys to clean up, and when they can't in 2 years, they'll throw these bums back in. Rinse, wash, repeat.