IIRC, Jared Diamond's thesis was civilizations collapse when they've done excess damage to their environment. Doesn't matter what happens to the seeds - they never get to grow into plants because the soil's gone bad. He builds a very strong case too. Devastatingly strong. With examples ranging from Easter Island to Haiti.
That was an amazing book. I see a future author writing an addendum, featuring the USA, amongst others.
I didn't have it in mind, though. Those societies did not fail because they were "socialist".
C_G meant "socialist", as far as I could figure out what he meant. This is never easy.
As for the "free trade" thing: I am an advocate of free trade between equal partners. I don't mean equal in "size", but in fundamentals. Poor farmers in India or Africa do not own their own land, that's the first thing that makes them different from us. Poor farmers in India or Africa do not, therefore, get to choose what the landowner wants planted.
I know several Indian farmers who live exceedingly well here in Canada on the proceeds of what to me seem to be very small farms in the Punjab. I mean as little as 10 or 20 acres. Their tenants do not live in Abbotsford in split-level modern homes and drive Escalades.
There are hundreds of thousands, likely many millions, of poor rural people who go hungry because the land that should be feeding them is planted to cash crops.