The President seldom if ever performs for himself on big decisions. There are so many lobbies and power interests moving their hands here and there, according to the tides of power.
It's just convenient for the masses to believe the President to be some kind of idiot (despite the fact that he is the President and they are random people which couldn't get that position if their lives dependent on it - or even much easier ones to get).
Trump is just uncouth and uncultured, with no filter. On some ways it's a disgrace. On others, it's a breath of honesty - between JFKs mafia types (and general non-worthiness, he was just made President by his family's money), Nixon's tapes, Reagans disastrous economics and policies, Bush's cowboyism, Bill Clinton's scandals, sex obsession and Epstein field trips, and Obama's backtracking on promises, warmongering, and empty rhetoric) most politicians are equally crass if not more, they just know how to not show it or show it in moderation.
Since Trump doesn't come from a politics background, he hasn't internalized this automatic filtering, instead he has been brought up on sales and media businesses, so he automatically takes the role of salesman and entertainer.
The Trade War with China thing was a long time coming for the interests of certain parts of the American establishment, and will be continued by Trumps successors. It wasn't some idiot's one-off.
And in those cases, unless you're clearly on top of the other side, there are lots of false bragging and BS symbolic moves that don't amount to much, so expect more of the "Tik Tok" style gestures in the years to come.
My 2 euro-cents.