Trade is not zero-sum. The US recovered from the Great Depression because FDR chose for it to recover. Obama has chosen not.
Mind elaborating there, bucko?
Trade is (usually) good for everyone in the short run, both the buyer and the seller. It'd wrong to assume that the collapse of America's massive export market in Germany, France and Asia was of
benefit to the US economy. Probably there were both positive and negative effects, with the negative strongly outweighing positive. Demand = government spending + private spending + balance of trade, so a reduction in exports would have worsened the recession.
Well, why did the US recover? Massive government stimulus. Trillions of dollars of it.