I wouldn't worry too much about the port fee thing. Trump is free to harm the Chinese interest in any way he can dream up. The blowback would be severe. The Chinese has many cards they haven't use yet. For example, while the U.S. and Israel are threatening Iran, what if Iran happen to find a bunch of very capable missiles on their doorstep? What about the Houthis? Suppose one day, they shoot a missile that could really damage the U.S. carrier. The Chinese can also levy taxes on Boeing made planes landing on Chinese airports. The U. S., being a player with global interests, could face a lot of challenges in many countries where it has interest.