You have to wonder now if there is a curse on Arsenal, something beyond a missing but vital fragment in their football DNA.
But then maybe it needs to be said right away that the latest team to provoke such speculation were magnificent – and that if Birmingham City's splendidly practical and intransigent manager Alex McLeish had made a deal to sell his soul for one performance he could take to his professional grave it is unlikely that he could have made one without inviting less cause to wonder if he had been short-changed.
No, if this is another Arsenal tragedy, another bone-jarring failure to bring home the fruit of endlessly beautiful football, it is not only that. It is also about how teams can be inspired to produced their best when it matters most and here we saw a classic example from the raw-boned team who now have to put aside the League Cup victory – one of the two that now represents the peak of their achievement down the years – and return to the scuffling business of Premier League survival.
Of course, it is also true that whatever the outcome of that vital battle, the great horde of Birmingham fans who invaded Wembley have memories to warm themselves down all the years.
Heroes such as Ben Foster, the author of some brilliant saves which resurrected the days when many thought he was a natural owner of the England jersey; Roger Johnson, a defender of both physical courage and relentless application; and big Nikola Zigic, as unwieldy as earth- moving equipment but a constant source of worry to Arsenal's embattled and – dare we say it at this bruising moment, inadequate central defence – are now worthy entrants to any old club's hall of fame.
City's on-field leadership from captain Stephen Carr was confirmation of the view of managers who know him best, men like McLeish and his former Tottenham boss George Graham, that you can travel into every corner of the game without finding a player with a superior approach to his work.
But when you have given to Birmingham what is entirely their due, there is an image of the day which draws you back quite relentlessly.
It is of Cesc Fabregas, who should have been orchestrating Arsenal's first significant winning moment in six haunting years, staring into the dusk and blowing his bubble gum in great puffs of what could only be interpreted as despair.
He looked hollow, as did his mentor Arsène Wenger and why would they not when Obafemi Martins gleefully exploited the terrible confusion which came late and fatally between Laurent Koscielny and Wojciech Szczesny?
This Carling Cup final, after all, was Arsenal's soft landing back on the football gold standard. Even without Fabregas and Theo Walcott, the recent conquerors of Barcelona surely had enough class and confidence to survive the traditionally fierce resolve of Birmingham whenever they are obliged to curb the creativity of Wenger's team.
For a little while, after Birmingham's tremendous start and the linesman's error that denied them a penalty and the advantage of a red card to Szczesny, it indeed seemed that in their ferocity and their spirit they had provoked the best from their opponents. Arsenal's equaliser carried us to the heart of their mystery or, if you will, their curse. It could not have been fashioned more exquisitely, or with more brilliant finishing, if the authors had given their address as the Nou Camp Stadium.
Jack Wilshere, who despite the unfolding disaster for his team, performed the prodigious feat of remaining arguably the most encouraging thing to happen to English football in a long time, flighted a superb drive against the bar – then saw the marvellous interchange of Andrei Arshavin cutting open Birmingham's left flank before delivering a cross to Robin van Persie. The Dutchman's volley was sensational. It carried us into the dimension of football excellence. But it didn't begin to deliver what Wenger – and Fabregas – craved.
It didn't provide at least a touch of the authority of winners which Arsenal need so desperately if they are to have a fighting chance of maintaining their slender lead over the Champions League favourites in Barcelona.
Who knows, it may come in that rarefied atmosphere – it may, finally, surface in the Premier League run-in to which they have elected themselves with some brilliant football. They may get the better of Manchester United in the FA Cup. They might conjure from the most unpromising sky an extraordinary treble, one to make the jubilation of Birmingham seem like a huge ado about really not that very much.
But that's not what the expression of Fabregas said. It was a disappointment that seemed to go beyond another mere defeat. There was an impassive stare, an almost glacial detachment from what was going on so bleakly before his eyes.
Was he, in his mind's eye, already packing his bags for hometown Barcelona? Maybe, maybe not but it was impossible not to speculate upon was the brittle mood of the team he was about to visit in a beaten dressing room.
You can only go to the mountain top so many times and come away unaffected by the yield of only defeat. Most worrying for the team who have set so many standards, who have trailed glory so persistently, is that the brilliant flash of Van Persie and the extraordinary touch and maturity of Wilshere were in the end just examples of lost opportunity.
Before the game Wenger addressed his demons and said that his team had to give the people what they wanted. They had to be more mature and they had to win something.
It did not seem an unreasonable request, not when you believe someone as sublimely gifted as Samir Nasri might take some of the responsibility created by the absence of Fabregas. But Nasri could display only the virtuosity of a natural-born talent.
He couldn't seize the moment and when this became obvious you wondered less about the curse and more the worrying DNA.