and then what? Trump put specific numbers about trade balance on paper with China during previous trade war, which China just ignored.

1. "Specific numbers about trade balance' isn't a negotiation term. It might be a prior that feeds into your position in negotiation, but it's not an outcome.

2. He lies when his lips move. When you're dealing with a pathological liar, there's no reason to believe anything he says that paints him in a good light - until it's been independently confirmed.