NEW YORK — Now I know how Cornwallis must have felt.

The story goes that the British, in surrendering at Yorktown to George Washington in 1781, played a popular tune called “The World Turned Upside Down.” Though there seems to be some doubt about the story’s accuracy, the symbolism is apt. It is also said that General Cornwallis refused to tender his sword to Washington, but sent a subordinate instead to perform the odious deed.

New Yorkers are feeling very British this morning, after the Boston Red Sox broke at least a portion of their notorious Curse by defeating the New York Yankees in Game 7 of the American League Championship Series. The Red Sox won the series, 4 games to 3 — after losing the first three games. At least Yankees manager Joe Torre, unlike Cornwallis, performed in defeat with the same dignity that has marked his demeanor in victory — so many victories — over the years.

What the Red Sox have accomplished will join a very short list of sports comebacks, and it is already hardening into baseball lore. All you need to know is that, over 100 years of what is now called postseason baseball, no team has ever overcome a 3 games to zero deficit. For the past four nights, the Red Sox have operated with no margin of error against a nemesis that has tormented them for more than three-quarters of a century.

Maybe you have to live in the northeast corridor to get the full import of this madness, but if the term Red Sox Nation has any meaning, the team’s triumph tonight will resonate far and wide, in red states and blue. For Yankees fans, last night’s developments represent not only the world turned upside down, but late breaking news that the universe is flat after all. And the Yankees have just walked off the edge.

IN WINNING LAST NIGHT, the Red Sox earned only their fifth trip to the World Series since 1918, which is the last year they managed to win one. That year, they employed a slugging outfielder and pitcher named Babe Ruth, who later was traded to the Yankees and helped make them the marquee name in American sports. I don’t know who started the idea of what became the Curse of the Bambino (one of Ruth’s many nicknames), but it has become a kind of neurotic religion in New England. Somehow the Red Sox were being punished for getting rid of the man who became baseball’s patron saint.

Bad deals happen all the time in baseball, but there is no arguing with results. Since 1918, the Yankees have won 26 World Series and appeared in 13 others. The Red Sox have won none. It was the Curse, they said. There is no arguing with self-fulfilling prophecies, either. And no arguing with New Englanders who, if they can’t win the Series, can at least fashion a mythology to explain their refusal to seize success.

What’s so stunning about last night’s Red Sox victory is not just that it came against the Yankees, though that is stunning enough. It is the manner in which they won. The magnitude of coming back from 3-0 against the Yankees, of all teams, seems capable of eradicating the Curse in one stroke.

You can’t get much more ridiculous than explaining 86 years of futility and near misses with a Curse. Imagine if corporate CEOs employed such an excuse for incompetence or malfeasance, or anyone else engaged in endeavors where performance mattered — which is to say, the rest of us. But with the Red Sox, and their poor cousins the Chicago Cubs, somehow passing the buck to causes less respectable than yesterday’s horoscope is supposed to be endearing.

What separates this Red Sox team from all the ones that preceded it is a focused determination to defeat this Curse nonsense. Every move they made in the past two seasons, capped off by the acquisition of Yankee killer Curt Schilling this winter, was designed for one reason, to beat the Yankees. They never said so, but the team finally seemed to realize what should have been obvious long ago: the Curse is a crock. Incompetence, occasional bad luck, the breaks of the game, and great Yankees teams explain all of the Red Sox disappointments the last 86 years.

The ball went through Bill Buckner’s legs in 1986 because Buckner, a near-great player of real grit and pluck, could barely bend over to field baseballs on two bad legs. Why was he out there? Because the Boston manager, John McNamara, was about as adept at managing as Manny Ramirez is at playing left field. But Boston fans, so enamored of the Curse and its built-in justifications for failure in high-stakes competition, chose to make Buckner’s life a living hell in Boston. To this day, Buckner is a punchline in Red Sox Nation.

That says most of what you need to know about the Red Sox and their sainted fans. In the next few days, we will read about how these long-suffering fans are receiving a modicum of repayment for their sacred loyalty. Yet Boston fans’ deepest loyalty is not to their beloved Red Sox but to their own sense of martyrdom. This identity cannot survive prosperity, and a new one will have to be refashioned if the Red Sox can take one final step.

THE CURSE, AS I SAY, is only partially about the Yankees. What it refers to ultimately is Boston’s inability to win the World Series since 1918. To be sure, the Yankees are a point of origin, and have often been front and center in the drama, but the dreaded chant of “1918” refers not to the Yankees but to the World Series. Now the Red Sox are back there.

But however the Red Sox fare, America should be Yankee Nation. That it is not, and that the Yankees are hated in favor of self-congratulatory losers like Boston and Chicago, does not speak well for our great country. The Yankees are America: confident, successful, and relentlessly focused on the future. Boston’s gloom and Chicago’s giddy ineptitude seem like very European tastes. A little bit Swedish, a little bit French…

If there is one thing Yankees and Red Sox fans have had in common this week, it is an all-pervasive East Coast insularity. How many fans of the two teams could remember that there was another series going on between the Cardinals and the Astros, let alone a presidential campaign? Everything was subordinated to this inter-city blood feud, in which everyone seemed to be looking for omens and signs of prophecy.

It reminds me of conversations I’ve had with an old atheist friend of mine. He has often quibbled with those who express the well-worn sentiment that “Everything happens for a reason.” He doesn’t believe things happen for any reason, and neither do I, though I am no atheist.

“But if you don’t believe there is any reason for anything,” he asks me, “how to believe in God?”

“Because God,” I say, wincing through my Catholicism, “is mostly indifferent, I think.”

Neither Red Sox nor Yankees fans have ever believed such a thing. But they both may have to start getting used to the idea.