A whole slew of small things that add up to a lot or mean a great deal to individual enterprises.
For example: When you enforce open importation of agricultural goods without adequate inspection, you reduce the cost of imports that compete with domestically produced goods. The socialized risk is of importing a pathogen or seed of a weed. Right now we have anopheles mosquitos in little artistic bamboo house plants. We have eupatorium (a weed) escaping all over the central coast (think of a dandelion bush that grows six feet tall and four feet wide with ten times the seed). Americans bear the risk of the cost of malaria or treating those problems which exist as an externality to the contractual participants who benefited by the import transaction.
See Part IV, Chapter 2 – Dangerous Species Act. :-)
This is to say nothing about the value of a local food supplier who is loyal to American interests. To export that production is to socialize the risk of a politically motivated interruption by which to create artificial shortage maintained by regulatory power. It will (no, not "may" but "will") work EXACTLY the same way the power crisis did, which is no accident because the principal proponents of this kind of liberalization and regulation are the same people who created that debacle.
Liberalize imports and investment overseas, regulate domestic production to death, control distribution with middlemen to screw the little people abroad (as is going on in the coffee market), drive people off their farms and into cities as cheap labor for factories (and teach them communism), socialize the risk of resulting shortages, and cash in. It's the same old game.
The solution isn't to cut off trade or hire more inspectors to test each strawberry. The solution is to choose produce carefully and wash it, anyway.
I do understand your concern about bringing in non-native species to a new area. That's a huge problem. Those of us in the south know all about fire ants and kudzu, neither of which were here a hundred years ago.
I don't think it can really be stopped without ripping up our roads, or closing our harbors and airports. This is going to be a matter of how to deal with the problem rather than how to prevent it. It's a given that it's going to happen. What we need is a rapid reaction taskforce to respond to it.
Supply disruptions, whether they are gamed or are the result some catastrophe, always play out the same way. New suppliers enter the market to capture the high prices. Supply increases, prices fall, everyone gets over it and moves on.
The purpose of CAFTA is to increase the supply of goods available to everyone. That's a good thing.
Thanks.