The answer to what you ask
The answer to what you ask starts to veer off on a tangent -- however -- in some circles what you talk about is called "relocalization", in other circles "buy local", in food circles it's called "locavore". Relocalization taken to the extreme you say probably isn't doable. Where are people to get their coffee and chocolate from if they're forced to grow it locally?
However - a huge amount of resources from transportation fuel to ship construction etc goes into globalization and globalized commerce. This causes environmental problems. Globalization should be minimized for environmental reasons.
Globalization should be minimized because it expands use of fossil fuel, and the reality of peak oil says we must seek ways to decrease fossil fuel use in order to have enough time for world society to develop adequate alternatives to fossil fuel.
Last reason to minimize globalization is the harm it does to local economies, by sending local GDP to other countries.
However as you say it's not viable to be 100% localized, and it makes sense to localize the things that can be localized and leave other things to global producers.