He admitted that his country won't survive a total cutoff. He's betting on China letting him keep a semblance of normalcy in these 90 days (which going by track record will be infinitely extended) by rerouting goods to US. It would be a mistake to allow the wounded snake a chance to live normally for another 90 days.This is unprecedented. Trump just handed for free a huge win to China.
In front of the entire world, China forced the US to back down in such a public and humiliating way. Not backed down directly against China, but backed down against the rest of the world because the US couldn't handle China alone
Pure demonstration of hard power. When you are playing at the global chessboard, sometimes you need to stake your flag and willingly fight till the end. This is such a global demonstration of power, America has lost a lot of prestige and legitimacy
China needs to keep the momentum going, hit US with such outrageous punishments in the next round that it will either break them or force Trump to stop the flow of Chinese goods and as such commit suicide again.
Taxing all US multinational company and blacklisting more of them will do it, probably.