Richard Nixon created a paranoid image of America as a "pitiful, helpless giant" if we did not prevail in South Vietnam. That idea was almost entirely military. That is, small countries around the world would pick on our navy, our merchant ships, possibly even our few colonies. They could do so because if a little country like Vietnam could outlast us, then any other country could also.
This paranoia was well accepted by an audience who grew up on military images of Czechoslovakia dismembered, on the dominos falling in Europe before Nazi aggression, and a possible Pearl Harbor style attack with nuclear weapons. But there was a counter-narrative. Even serious conservatives knew that the great Empires of the past had fallen from within.
Perhaps someone else has already written a book on the twilight of empire. My point here is that the result of the Vietnam misadventure did not turn America into a helpless giant. However, there are two competing narratives as to what internal changes happened in the USA to make us increasingly helpless before world events.
More than any other actual enemy, Osama Bin Laden articulated the method of defeating America. He was frank in his admission that he, even with the help of the entire Arab world, could not "take over" America. But the way to do it would be to ruin the economy of the USA. In that, he had no better helper than George Bush the Younger, who actively destroyed the prosperity of the Clinton-Gore years. Because of the media failures, and the general power of the top one percent, Obama has not broken free of the Bush legacy on Taxes and civil liberties.
So the two narratives of "what's wrong with the direction of the country," amount to one group saying that the top one percent has been given too much. The other side claims that the bottom 50 percent has been given too much. In the resulting gridlock, we see the vision emerging of the pitiful, helpless giant.
Yes, we had the resources to attack Libya for a short time. But no one thinks we have the power to extend our involvement the way we did in Iraq or Afganistan. The War on Drugs is clearly a loser with drugs having won--at great expense to the public and to civil liberties. The War on Terror also strongly suggests that Terror won. Any trip to the airport will indicate how pitiful and helpless we are. Plus the constant appeals to fear--which mostly work--shows that Terror is alive and well at election time.
France was the richest country in Europe in 1789--but the government was bankrupt. Likewise, the USA is bankrupt for the same reason as France: the unwillingness to tax people who actually have the money. So now we see "pitiful helpless" narratives being spun and more of the bottom half of the country coming under attack. Public school are being destroyed by the foolishness of standardized testing; all manner of public safety regulations are being taken apart at the state level; politicians can discuss ending Medicare and Social Security without fearing electoral consequences; and women are under attack on numerous fronts.
So, in ways that Richard Nixon did not imagine, we have indeed become a pitiful, helpless giant. China, Brazil, and India are eating our lunch. A second tier of countries like Mexico, Venezula, and Chile are poised for advancement at our expense. Yet we are stuck in ancient debates from the 1980s, or in the case of some older people 1938 or 1968. Meanwhile, popular culture moves forward, and someday that popular culture may again inform our political culture.