"Dependence". Look, maaan. The little red squiggly that your browser inserts under your words means that they aren't words. It isn't that difficult to understand your spelling checker.
Your argument that every country should be self-sufficient is woefully shortsighted. Let's continue with your notion and suggest that every state should be self-sufficient, for why should Maine have to depend on North Carolina? But, let's not stop there. I mean, your community in Bangor can surely not rely on products from Fairfield. And all this relies on community, which is notoriously chaotic and irresponsible!
So, let's insist that every family must be able to provide for all of its own needs without any reliance on others. Wait! Every individual! You can by no means trust anyone other than yourself.
Now, get cracking. It's time to weed the fields, feed the chickens, shear the sheep, haul water, harvest some trees, and continue the search for good clay and iron ore. If you get sick, you're weak! Go ahead and die.
At least, in your glorious self-sufficient paradise, you will have no need for money.