I am afraid to hear the answer.
Be not afraid.
Yes, American profligacy should be a concern. But the metrics we employ are often ill-derived: spending (consumer durables are storehouses of value), saving (we don't mark much of our 'savings' to market), etc.
The current account deficit is not problematic. In fact, the know of no 'sequential causal relationship' between capital flows and spending. We just can't say at all that the capital account is a function of the current account...
Our national debt, taken alone, is staggering. Even so, we have a 12 trillion dollar economy, which continues to post non-inflationary output growth numbers above the long term trend, and in excess of the budget deficit.