Most of our potash comes from Canada, but surely the US is self-sufficient in nitrogen fertilizer (since it is made from natural gas, which is really cheap in the US) and ISTR it's being close to being self-sufficient in phosphate, too.

Maybe. But as an OSS developer, I find it cozy that even domestic food production has a certain global component. I like the image of a global community helping each other, just as we do in software projects.

I mean, if American companies had rejected Linux/Ruby/Lua because "they are foreign goods, born in Finland/Japan/Brazil", were it better?