I think you mistake a trade war for ordinary international business.
In ordinary international business there are those that prevail and those that do not. It happens all the time continuously.
The current efforts by our persident are sepcifically directed at removing the edge of unfair competition.
Regardless of the President's intent, his tariff increases have been followed be retaliatory tariff increases on the part of China. If he continues to escalate the matter to more and more imports then China will continue to retaliate. That's a trade war.
The end result may be what Trump wants - fairer competition. But getting there will take time. And in the mean time people and businesses will suffer.