> This comes from the dated perspective that free trade is universally good.

lol, ok, I'll bite. Other than one side might try to change the rules; why should I believe is free trade is no longer universally good? What is the specific argument?

Because if the argument is that one side might impose taxes, duh? But that's no longer free trade is it?

If both sides were willing to play fair, why wouldn't that be better? And why shouldn't we all be trying to "encourage" everyone to play fair?

There are many arguments but the most straightforward one is that a country may decide that preserving particular industries is in their security interest. That can be extended to culture as well.

Japan closed itself off from the world for centuries during the Edo period. One could say that they suffered economically due to that, but on the other hand, they ended up creating one of the more unique cultures in the world, developing in ways very different from others. It's an interesting kind of diversity.

Food production is a huge one. We don't want highly optimized farming where only the most efficient growers feed everyone else because that has the risk of global famine if something fails there. The more a system is optimized, the closer to failure it is. Same goes for all other kinds of production but food is really important compared to, say, CPUs or cars.