They seemed to say, in handing Obama a large victory over the hawkish John McCain, Navy pilot, Vietnam veteran and former prisoner of war, “We know where we stand in a new century. It isn’t ‘ours,’ as the ‘American century’ was. We’re in a new place. New things will be required of us.”

In November, we will have a sign as to whether Americans are willing now to accept that they have arrived in a new era — or whether they will risk falling behind in it.

Against this background, the November 2010 elections bring the possibility of a broad retreat from “the Obama moment.” Shouts of “Socialism!” — a tired ploy with a long history in American politics — arise at the merest hint of change or an adjusted perspective.

A “new right,” influential beyond anyone’s imagining in 2008, asserts in dozens of ways that nothing is different for Americans or America: It is still “our century,” and we ought to take it back along with “our country.”

The thought, plainly enough, tempts many Americans — some of whom, one must assume by the numbers, stood with Obama two years ago. In short, America may be about to flinch from a moment of courageous self-recognition.

To an American who has lived many years in other countries, the questions framed by the fall 2010 election campaign are wrong from the start. Can the American century march on? Is it wise to pursue that goal? Can the United States recapture its place in the world just as it was over the past half-century? Is its stainless-steel faith in unfettered markets at home still justified?

These are the implicit questions this year, but they are not the questions anyone ought to welcome — they are yesterday’s questions.

The questions that ought to be addressed are when did the American century end — and what can Americans learn about the future by identifying a fundamental turning point in their recent past? These questions suggest we stand at the far end of an era. And this is precisely what we must come to terms with as a nation, whether or not we find it a comfortable undertaking.

The European model — one form or another of social democracy — now competes with Chicago School capitalism.

Answering the “when” will tell us much. Most people who accept that the American century is behind us would nominate 2001 — September 11th, to be more precise. Something turned at a very sharp angle that dreadful day. Something ended and something began, for ends are always beginnings, too.

There is much worth considering in the thought that 2001 is the right date. That autumn, after the airplanes hit Manhattan and elsewhere, was a significant moment, distinguished by its uncertainty.

Many Americans soul-searched: Maybe we ought to do things differently, a lot of us speculated — to think of ourselves in a new way, to be more aware of cause and effect and our place among others. I think of that time now as one of constructive confusion.

The American century might have ended in 2001, for what happened then, stripped to its core, is that the United States joined the process known simply as history. We could no longer ignore its incessant knock, for we were no longer immune from its forces. In the American vocabulary, the narrative of “exceptionalism” had in an instant lost its validity.

But that brief period of fertile questioning and apparent drift — nerve-wracking and full of promise all at once — ended decisively the following January. On January 29, 2002, George W. Bush delivered his “Axis of Evil” speech. His first State of the Union performance, in retrospect, seems purposely intended to draw a line under any straying from America’s old idea of itself — and a return to the orthodoxy since 1945.

The moment was significant. It signaled that Americans were to stagger on for another seven years. Every effort was made thenceforth to salvage the historic sense of the nation’s exceptional mission (a favorite Bush-era word), give Americans a new enemy — and keep history at bay.

The autumn of 2008 will emerge as the point of exhaustion for the postwar American model.

Iraq and Afghanistan followed, as if to prove the point. “History does not define us,” we can recall Bush asserting at this time. “We define it.” For once, the mistake-prone president had gone curiously straight to the point.

This is why the Bush years were, for many Americans, so forlorn and so essentially nostalgic in character. The nation was invited to walk around in a sepia-stained photograph of itself.

But then came 2008, another year of momentous change. The year 2001 is when the lights in the theater began to come up, we might say. It was in 2008 that the drama ended, for three events in quick succession that year marked the end of the American century in several of its dimensions.

The first of these was the brief but significant war in August between Georgia and Russia. The Bush Administration seems to have done all it could to encourage Mikheil Saakashvili, Georgia’s Western president, in his restless opposition to the Russians. But then, the America of limitless power found its limit when Washington gave every appearance of standing by Tbilisi as Moscow came near and turned out to be powerless to do so.

Hard upon this came the financial collapse. Few Americans think of it as such (just as most are shy of a sound interpretation of the Georgia confrontation), but the autumn of 2008 will emerge as the point of exhaustion for the postwar American model, at least in its most extreme aspects.

During the Bush years, the nation was invited to walk around in a sepia-stained photograph of itself.

The shrill insistence on its efficacy we all heard in the triumphalist 1990s is already quieted. And it is plain from the assertions of America’s friends across the Atlantic and the preferences of numerous others that the European model — one form or another of social democracy — now competes with Chicago School capitalism.

Finally came Obama’s election. Another part of America spoke, and it produced a moment of magnificent redress. The “we-and-they” narrative, the self-and-other narrative that had driven American history since the earliest days of European settlement, seemed to yield to something new. In his very being, Obama represented that simple but instantly charged word — “change.”

And from that moment onward, the American conversation did change. This, indeed, seems to be what Obama meant in making the thought so central: to change the way Americans think, understand themselves and talk — among themselves and to others. Do this, he seemed to urge, and all the questions of policy — what to do — will follow.

It is against this background that Americans seem so prone now to flinching. Part of this must be marked down as Obama’s fault and part, no doubt, reflects our economic uncertainties. But the question runs deeper than either politics or the economy. It is not the extraordinary, perplexing reversal of popular sentiment, say, on the healthcare issue. And it is not Obama’s decision — almost certainly a fraught one for him — to yield to the Pentagon in advancing the U.S. commitment in Afghanistan.

Neither is it the very limited progress he has made in reaching out to the Islamic world — one of his earliest and most interesting moves. The question is how much or little Americans have proven willing to think anew.

America may be about to flinch from a moment of courageous self-recognition.

There is no going back to any time before 2008 — or 2001, if one chooses that year in an interpretation of when American predominance drew to a decisive close.

History has turned, and this is no one’s choice one way or the other. In November, we will have a sign as to whether Americans are willing now to accept that they have arrived in a new era — or whether, for fear of change, they will risk falling behind in it. This is America’s choice.