Quote Originally Posted by Animeniax
There is a lot to be gained by being self-reliant on your own country's products and manufacturing power.
There is also a lot to be lost. Each country is unique. Their level of technology, population size, land mass, natural resources all factor in as to what they do best. It is probably possible that every country could develop in such a way that they can support their own without trading, but that would mean producing some products in inefficient ways.

Sealed exonomies like that defy the basic axiom of economics: to best satisfy our infinite wants with finite resources.

As such, the idea of wanting to be self sufficient is not enough to compensate for the lost resources in achieving that. Hence the globalisation trend.