Regarding the recent talk of negotiations, I have to remind you of the semi-secretive meeting between Trump and US giant retail companies where Trump was told by them that if he continues down this path, they'll run out of everything within weeks and there'll be chaos. Accompanied by the ongoing protests across USA and the dumping of US stock market where massive chunk of it vanished in a blinking of an eye, practically forced Trump to beg for negotiations...
In short Trump had the this delusion that US economy is still strong. He quickly realized that US economy is indeed one of the most fragile economies in the world thanks to decades of corruption and bad decisions...
The US have always considered China as a great adversary,a close competitor and a difficult rival to deal with. They have been looking for ways to wreck China economy and have been spreading propaganda to decimate the reputation China have built over the years. However China have succeeded in putting strategic measures in place that have help her to counter any US attacks on her economy and that's why US retaliation against China haven't cause enough harm to her economy regardless of the current impose high tariff fees on her goods.Trump been delusional might be due to the wrong advise he has been receiving from his economy experts/teams. Those wrong advisers have clouded his thoughts from seeing the truth and accepting on time that this path would only lead to catastrophic. I vividly concur with you that the US economy is fragile. This trade war have really exposed a lot about the US economy,that the US cannot sustain her economy for so long without trading with other countries, specifically China. If the negotiation with China eventually bears good fruits,the US would learn never to go on a trade war with China ever again.