That's a good point but it goes back much further than that, back to

https://en.wikipedia.org/wiki/Corn_Laws

The WTO has been in a stalemate since the Seattle riots of 1999 because developed countries insist on subsidizing and protecting farmers of major crops (the odd thing is that there is little dirigisme for healthy foods like broccoli and spinach but a lot for mass carbohydrates such as corn, sugar,...) but developing countries won't further open any other kind of trade unless the developed world opens up in agriculture.

Convincing any country, let alone the USA, to give up national security for policy ideals is going to be tough. Food security as a national interest is an easy argument for the agricultural lobby to make. Now it's starting with semiconductors.

Agricultural protectionism creates political conflict inside the country that practices it.

The Corn Laws were so divisive in the UK because they were good for legacy nobles who owned vast amounts of rural land but bad for city dewellers and the emerging class of factory owners.

Note the story of

https://en.wikipedia.org/wiki/U.S._Sugar

where particularly

   ... sugarcane in the United States remains nearly twice as expensive per pound 
   as in other developed countries due to the failure the industry would face
   without government subsidies

even if you can say that the last things Americans need is more cheap sugar.

In the case of the US our comparative advantage for producing food is large and we don't improve national security by maximizing our production, we just use more fertilizer and get a bigger dead spot where the Mississippi river enters the ocean.

> (the odd thing is that there is little dirigisme for healthy foods like broccoli and spinach but a lot for mass carbohydrates such as corn, sugar,...)

Mass carbs are how you feed people in the kind of emergency that might make having a strong domestic food supply extremely nice. People can always backyard-garden some greens. If you've got enough corn, wheat, rice, and/or potatoes (maybe), the rest will sort itself out. If you're lacking in those, people are gonna die.

> the odd thing is that there is little dirigisme for healthy foods like broccoli and spinach but a lot for mass carbohydrates

You can't run a nation on broccoli and spinach (unless your population consists of Popeye-clones) while you can run it on starchy foods like wheat, corn and potatoes. They may not be the most healthy alternatives but they'll keep you - and your army - alive to live and fight another day. If a nation can not get any broccoli or spinach they'll just get some other green vegetables or do without. If the nation can not get any bulk starch products it is in dire straits. The high status of green vegetables is more of a symptom of overabundance than of their capacity to feed a nation. They certainly make for a healthy addition to a diet but they lack a number of essential things - proteins and fat as well as some vitamins, B-12 being the hardest to find in plant-based foods.

To be fair to the US, it goes back WAYYYY further than that.

The dirty secret of international fair trade, is that there is no international fair trade. And there never has been.

It's not the fault of the US for ag subsidies. Not even the fault of China if we're being honest. It's just how things have always been since before the Phoenecians even.

Pro tip:

"Empires", are not built on "fair trade".

Yep. It's nobody's fault that, surprise surprise, countries look out for their own best interests.

All countries have historically had tariffs. So, “broken” would mean a break from this free trade cultism that happened after large economies espoused the Austrian School of economics type free trade.

And US had no reason to break it because until maybe 2005 US was the biggest beneficiary of this system.