It's true that America cannot command the same respect abroad that it once did, when its domestic economy is faltering. As former Secretary of State Condoleezza Rice said, in a sparkling speech that contrasted starkly with Romney's banal delivery: "When the world looks to America, they look to us because we are the most successful economic and political experiment in human history. That is the true basis of American exceptionalism."
At least it used to be so.
While traveling around the globe after communism's fall in the early 1990s, I heard Asians and Africans and Middle Easterners and even Russians repeatedly say they admired the American model because it worked and guaranteed prosperity. They wanted to emulate America because they thought we knew what we were doing and had a formula that combined political freedoms with economic success.
Yet, today many Asians, Africans, and Arabs are now looking to other models, including more centralized economies such as China's, which lack political and civic freedoms. So what has gone wrong?
Romney argued on Thursday the fault lies with Obama, who failed to deliver new jobs, cut the deficit, or help small businesses. The Republican candidate pledged to create 12 million jobs (no details), cut the deficit, lower taxes, and promote free trade.
He repeated over and over the need for a "united America" to reach these goals. Yet, as he well knows, a stunning lack of unity is undercutting our country at home and abroad.
"Americans always come together after elections," Romney said, adding he wished Obama had succeeded after taking office. The sheer cynicism of these latter remarks is breathtaking, given the Republican pledge from the start to undermine Obama. This goes to the heart of why the world now doubts America's ability to lead.
America's brand has declined because foreigners believe we can't get our political act together. When I travel abroad now, I hear doubts about our competence and skepticism about whether we can fix a broken political system. Foreign leaders and publics believe our country is so riven by political partisanship that it can't repair our economy.
These doubts took root during the Iraq war, when the Bush team's postwar incompetence turned a military success into a political triumph for the Iranians. (I agree with Romney that Obama can't blame everything on his predecessor, but neither can Republicans claim history began in 2008.)
Over and over in Iraq, and in the Mideast, bewildered Arabs repeated this mantra to me in the 2000s: "We thought you Americans could do anything. How could you have made such a mess in Baghdad?"
The world's skepticism about the U.S. model intensified with the 2008 financial crash, a product of too much deregulation and corruption on Wall Street. Keep in mind that the financial contagion that shook the world started here, another blot on the U.S. model. And the deficit ballooned on George W. Bush's watch.
Which brings us to Obama and Romney's critique.
As Romney proclaimed, unity is required to reduce the deficit and get the economy moving. But the world sees a dysfunctional system in which U.S. political parties cannot work together on deficit reduction. And - as any fair-minded observer would note - the Obama White House has been far more open to compromise than the Republican base.
Foreign leaders, both allies and foes, were astonished when Republican hard-liners pushed the country toward default rather than raise the debt limit. This is what led to the lowering of the U.S. credit rating (Paul Ryan, take note).
World leaders are bemused when Republicans insist there can be no revenue increases, only tax and spending cuts, to balance the budget. They understand such ideological rigidity means the deficit problem won't be solved.
They notice when Romney calls for a huge increase in defense spending, coupled with deep tax cuts, which can only lead (as it did in the Reagan era) to a large deficit increase. They can do the math, even if the Republicans refuse to.
It is this disturbing display in Washington, more than Obama's foreign policy missteps, that convinces foreign leaders America is declining.
I'm a believer in America's capacity for renewal. But the U.S. economy won't right itself without leaders who truly embrace national unity and are willing to compromise to make our economic system function.
If Romney really wants to revive the U.S. brand, he'll have to pay more than lip service to the words united America. That would give real meaning to the phrase "lead from the front."
E-mail Trudy Rubin