1.History shows Americans have overcome worse
For starters, it's helpful to remember that Americans have overcome great obstacles in the past, when many doubted success. The American Revolution, the Civil War, and the great world wars easily come to mind. They point to a can-do ability that supersedes circumstances.
Despite talk of two Americas and the popularity of secessionist petitions (hundreds of thousands of people have signed them for every state in the Union), it is inconceivable that there will be a repeat of the Civil War. Similarly, the probability of a great-power or global war is virtually nil.
The 'good old days' weren't so good
The assessment of American decline is not as persuasive as it might appear, depending, as it does, on the "good old days" being as rosy as many people recall. At least in foreign policy, the US is often said to have achieved "hegemony" – having its way – after World War II, only to have become impotent in recent years. But this alleged period of postwar dominance was rife with strategic setbacks. Among them:
The emergence of seven additional nuclear-weapons states between 1945 and 2000 (Russia, Britain, France, China, India, Israel, and Pakistan); a series of strategic crises (the Suez Crisis of 1956, the Berlin Crisis of 1958, and the Cuban Missile Crisis of 1962); the costly and protracted war in Vietnam and beyond that ended in US defeat and the rise of the brutal Khmer Rouge in Cambodia; the OPEC oil embargo of 1973 that contributed to US stagflation; and the Iranian Revolution of 1979.
America's strengths are not to be discounted
Let's not forget America's strengths. It is the only country that can project military power globally. While China will increasingly challenge its power-projection capabilities in the Asia-Pacific, it is unlikely to rival US military capabilities on a global scale for some time.
The US accounts for roughly a fifth of gross world product, has the world's only reserve currency, maintains a higher-education system that attracts the most international students, and nurtures an entrepreneurial environment that continues to entice many of the world's most creative thinkers.
While America's relative advantage in these categories may well continue to diminish, the country will remain a linchpin of the global economy.
Progress in housing market and manufacturing sector
Going forward, there are grounds for optimism. The Economist notes that US housing prices have stabilized and "even made small but steady gains in recent months." The Atlantic documents the "sustainable, just-getting-started return of manufacturing to the United States" and the potential reversal of a "decades-long relocation of American jobs to Asia."
America's wealth of resources
British historian Niall Ferguson reports that the US "is aging much less quickly than countries like Japan and Germany" and touts its reserves of fossil fuels and minerals worth at least $30 trillion. The big debate now: Should the US permit natural-gas exports?
While the liberal international order may be frail and fractious, what is there to rival it? Indeed, the National Intelligence Council, in its recent report on global trends projected to 2030, says: "The replacement of the United States by another global power and erection of a new international order seems the least likely outcome [for America's role] in this time period."
Nor is it clear that any countries or coalitions are agitating to assume America's role, let alone responsibility for leading a new system – even China. At the beginning of the year, Jimmy Carter's former national security adviser, Zbigniew Brzezinski, related a story in which a top Chinese policymaker quipped to one of his US counterparts, "please, let America not decline too quickly." Precipitous US decline, after all, would likely destabilize the global commons upon which China's growth depends.
America has it better than many others
However many challenges America faces, they are not as severe as those confronting others. This is not to delight in schadenfreude, a sentiment both morally perverse and strategically misguided. But it provides context.
Across the Atlantic, for instance, population decline, anemic growth, and resurgent nationalism challenge the European Union's dream of cohesion.
As for China, consider just a few of the challenges with which the new president, Xi Jinping, and his successors will have to grapple – a huge influx of the population to cities, a sharp drop in the working-age population, costly environmental degradation, an export-dependent economy, and nervous neighbors.
Going forward, it would be useful to recall Richard Nixon's rebuttal to the declinists of his time. He advised Americans: "Don't let the problem of the moment obscure the great things that are going on in this country."
Ali Wyne is an associate of the Harvard Kennedy School's Belfer Center for Science and International Affairs and a contributing analyst at Wikistrat. Follow him on Big Think, Twitter (@Ali_Wyne), and Facebook.