The breaking point for China on trade will be when there is social unrest. These bureucrats/tirants aren't used to be pushed around, they will fight Trump but the real leverage is with the US, its the largest importer in the world. If they cut or credibly threaten to cut down imports from China, this could lead to a recession there. This would lead to civil unrest and the government could fall. Its this fear that is likely to get China to bend over and change things. Of course, all of this will come at the expense of short-term volatility. The Trump plan is will involve lots of short-term volatility, if his plans play out though, long-term the US will be better off