The roaring 20's trade was 5 Billion per yer in current dollars on average. That is minuscule, almost a statistical anomaly. That is self sufficiency.
Trade isn't a problem, and never has been. What is hurting this nation economically is malinvestment consequent to credit manipulations by the government. If the government's (and the public's) borrowing were constrained by real interest rates the middle class wouldn't see their future mortgaged to buy votes.
Gibberish.
Are you unaware of how the government manipulates the credit markets and the currency, and the effects that has on consumption and investment?
Without massive government debt issuance there can be no long term trade imbalances. Cutting off trade doesn't address the problem, it just means we can no longer export the consequences of our inflation to others. Even massive government debt issuance doesn't have an unlimited horizon. Eventually the interest payments themselves swamp the taxes collected, and at that point the reality of what politicians have wrought is brought home at once: witness Greece.
Freedom to trade is not the problem, but the politicians and bankers who profit from our system of government debt and inflation absolutely love for you to ignore them and will gladly support you scapegoating producers.