What If ...? I'm just askin'!

First let me set up the background for why I'm eventually going to ask the big "What If?" question:

In this era of Globalization it seems that everyone assumes that for any country to be prosperous they must be involved in international trade. Let's call that assumption #1.

The second assumption (let's call this part, #2a) is that there is a cap on the amount of the total wealth of all nations combined. Assumption #2b is that there must be a balance of trade between each trading partner, otherwise one party would deplete the wealth of others.

So, here's the the question:
What if, for some reason, tomorrow, there was no other country but us? As I ask this question, I'm using a laptop computer built of components manufactured in Asia. And eating a banana from a Central American country. I had pineapple on my pizza last night which I'm sure didn't come from Hawai'i (Go tour the Dole Plantation on O'ahu, then you'll see why I'm doubting).

We won WWII, because we could support our campaign abroad and, with shared sacrifice, maintain our families at home, while our enemies could not. The Soviet Union crumbled because their Cold War military expenses decimated their limited economy. Since we've become a country that is a net importer and have sent our manufacturing jobs elsewhere, I doubt we could repeat those successes again.

So, what if we played "pretend", a type of War Gaming. The scenario is: We are alone. Do we have the ability to make our own laptop computer, from elemental minerals, through engineering and manufacturing to provide the product to sell to Americans at a price that is affordable?

Can we grow our own bananas in our southern states, or Hawai'i, American Samoa, Guam, US Virgin Islands or any of our territories?

We send our scrap iron to China to be made into new products to be sent back over here, could we mine the minerals and manufacture steel from scratch again if we wanted to?

I'm sure the answer would be, that if we had to, we could supply everything we need to support our American Lifestyle. We don't now because everything would be too expensive in today's global economy. It's impossible to compete with imports where their expense to hire people to do the work is a fraction of our domestic labor costs.

If there were no global-economy would we just not resume making things because it would cost too much? (Hey, I want to eat bananas and pineapple, and this laptop isn't going to last forever.) Or would we look at why it costs too much and adjust whatever is out-of-wack?

Do we have to be exporting more widgets than we have domestic demand for to be a functioning economy or can our wealth just circulate amongst ourselves?

Does a capitalist economy have to constantly "grow" to function? And, if so, does that mean that some countries have to decline so that others can prosper?

I'm not advocating Protectionist measures, simply because I'm told the Smoot-Hawley Act helped cause the 1930's Depression and because everybody important says that protectionism is a bad thing. But shouldn't we take a look at what we're doing and see if there is a way to make sure that we can take care of ourselves, no matter what?

Are our assumptions valid?

Couldn't we pay the average American wage, (which is $20/hr.) to Americans to make our computers, flat-screen TV's, iPods, iPads, running shoes, jackets and just about everything else?

I'm just askin'.