The scarcely believable sequence of words and pictures that reached us from Japan yesterday suggested that the Irish camp has disintegrated to a level of dysfunction that is staggering. That Niall Quinn has writ himself a large and celestial part in a sorry drama that really had nothing to do with him is the latest manifestation of a fatal and unforgivable lapse in management and administration.

When Mick McCarthy went on air to essentially contradict Quinn's verdict that the Roy Keane expulsion was beyond resolution it became clear that the natural orders that preserve the cohesion of any squad had ceased to exist.

The ultimate consequences of this shameful and petty episode are painfully set in stone at this stage. Mick McCarthy's position as Irish manager has become untenable and resignation will become the likelihood when Ireland's interests in this World Cup end - and arguably, they have already ceased.

It is uncertain anyway that McCarthy, a proud and honourable man, will wish to continue after the surreal collapse of his authority. The failure to right this fiasco renders it, sadly the terrible and definitive legacy of an era through which McCarthy had painstakingly developed into a manager of considerable standing.

What ought to be his finest hour has free-fallen into a nightmare of pride and pettiness that has somehow become a metaphor for what this country stands for.

Many people are understandably growing increasingly uneasy at the hysteria that this stand-off between McCarthy and Roy Keane has provoked. The old maxim about football not being a matter of life or death has been invoked. And the thousands of calls and missives have been both fascinating and extreme. Why the madness?

What possessed a caller on RTÉ radio, an articulate and rational soccer fan who said that he has missed three Irish home soccer internationals since 1973 - think of that - to declare he is going to cheer for Cameroon on Saturday? The reason is that many people believe that Roy Keane stands for a rare brilliance, the unflinching and unapologetic pursuit of excellence and that he has been obstructed and punished for that pursuit. Keane is no angel, as he has elaborated in his many media purges over the past few days. Last Tuesday in Saipan, he was hotheaded and hasty and foolish when he threatened to leave the island. But he reconsidered and he was probably privately embarrassed at the exposure the incident received.

Since then, he has never once lost focus of the reasons for his anger. His comments in this newspaper last Thursday were compelling and intelligent and justified.

In his reaction, Mick McCarthy demonstrated a succinct failure to manage. He allowed emotional slants to set in motion the swift chain of events that led to the sacking and dismissal of Roy Keane, the very soul of the Irish team. It was an act of terrible folly. The very fact that he had left himself open in recent days to a phone call from the Irish captain was an implicit acknowledgement of that ill-begotten haste.

Whatever Keane said to McCarthy was doubtless unpleasant but it ought to have been apparent that someone with his combustible temperament would react badly to being dressed down in front of his team-mates.

And the disgraceful hours of isolation that Keane endured following his dismissal were far more grievous and hurtful than any words, however foul and spiteful. To leave a player of 10 years-standing to arrange his way home from a remote island is terrible.

That the FAI expected Roy Keane to apologise after that cold abandonment is a further example of their collective ineptitude. In private, Keane may well have met McCarthy half way but Niall Quinn's admission that the players were anxiously awaiting word of Keane's mea culpa live on television is funny and touching and tragic all at once.

Keane could not apologise because he believes there is nothing to apologise for. He raged against a cult of imperfection, of doing things wrong, of messing up, of plain carelessness that has long been the hallmarks of the FAI. Mick McCarthy and his years of patient team-building have been betrayed by the FAI as much as Keane. But McCarthy has the misfortune of being manager. It was up to him to ensure that the mind-boggling cock-ups that so enervated Keane did not happen.

Roy Keane ought to have been flown back to Japan with no preconditions or daft demands. Team sports are primal and elastic; had McCarthy seen to welcome back Keane into the squad, then all reservations would have dissolved.

Players just want to play and on the strongest team possible. Chances are, the young stars of this side, Ireland's future, are devastated at the thought of not lining out alongside their childhood inspiration.

Now that Roy Keane will not wear the Irish shirt on Saturday morning, a shameful and mean hour in Irish sport and life has come to pass. Arguably the greatest Irish sportsman of all time has been denied the right to grace the high theatre of world sport in a summer that sees him at the peak of his fiery and singular genius.

And for what? The absence of a hollow apology? The appalling thing is that the worst is probably yet to come. If Niall Quinn's ravaged expression is an accurate reading, then the Republic's squad is mentally washed out. It can't even be said that this has affected preparation. It has as good as been utterly abandoned. Ironically, had Roy Keane made it to Japan, he would probably have been the most well rested and serene of all the Irish players. For him, there is no moral dilemma in this. Evidently, that was not the case in Japan.

On Saturday, Cameroon could inflict an on-field humiliation to match the behind-the-scenes embarrassments. The one hope is that Cameroon may grow scared of the notion of facing a side that might play with the desperation of the unhinged.

The sad thing is, of course, that many Irish people can't bring themselves to care anymore. Think back to the carnival night in Lansdowne Road a few weeks ago. It will be a long, long time before we arrive at such beautiful scenes again. Mick McCarthy did much to inspire them and somehow has let it all go up in flames. And the fallout from this may well affect his reputation among clubs rumoured to be considering poaching him.

Everything is uncertain now. We may never witness Roy Keane's magnificence in Lansdowne again. We may not see McCarthy on the touch lines again. Irish soccer has taken a monumental blow and the buffoons who run the FAI have to stand up and accept the blame. Cathal Dervan may yet get to hear his miserable chorus of booing whenever Ireland next play at Lansdowne. But not, as he once wished, at Roy Keane.

If this is the end of Roy Keane's international career, then Ireland has become a smaller and meaner place.