>politically enforced sustainability and diversity
This is important, and politically difficult. I mean, we subsidize farms to farm in America because it makes us much more secure against all sorts of potential problems. I, for one, think farm subsidies, if well done, are a very good use of my defense tax dollar.
But it's important that we see those subsidies as a defense subsidy and not, you know, just a handout to a particular class of people; This means that we need sustainable farming practices and we need crop diversity, as those are the only way to defend against some of the threats we face.
(I mean, I personally see it as "you don't want a subsidy? do what you like. But if you want a subsidy? you have to follow these best practices." then you set the subsidy numbers based on how many acres you think we need for that sort of thing.)
Not exactly the same but as long as we have national reservoirs and get politically enforced sustainability and diversity we should be fine.