Both bargaining chip and blunt instrument. Seems to be working better than even I expected!

Free trade only works if there is exactly that: Free trade. As soon as a country manipulates trade in some way, presumably to benefit itself, there is no free trade so further adherence to it is merely wishful thinking. If trade manipulation was such a losers gambit then it wouldn't be used so successfully against the US by so many other countries in the world. Trade wars have costs and making all sides pay them makes a balance and hopefully ends them.