The Garda Commissioner Nóirín O’Sullivan has announced that she is to retire. She made the decision in reaction to the “unending cycle” of scrutiny to which she has been subjected since she took up office.

The Commissioner – who took over from the previous commissioner Martin Callinan in March 2014, when he was forced into resignation by the Government – has been embattled ever since.

While she presented herself as a reformer, the force over which she exercised ultimate responsibility and control, remained dogged by controversy. The latest blow to the prestige and integrity of the Gardaí was the breathalyser scandal, with over a million tests apparently being fabricated by rank and file members.

While there are those who would see that as a relatively unimportant issue, alongside the abuses of power that seem to be an ongoing fact of life within the Gardaí, the realisation that 14,600 people were wrongly convicted, and sanctions imposed, turns the image of the Gardaí as protectors of the citizens of Ireland on its head.

While it began when Martin Callinan was in charge, the disgraceful treatment of Garda whistleblowers Maurice McCabe and John Wilson – among others – represented a shocking indictment of the one-eyed culture within the State’s primary law enforcement agency.

And finally, there were the financial irregularities at the Garda Training College – an incident which suggests that the custodians of the law were not above breaking it if and when it suited them.

Very few people have suggested that Nóirín O’Sullivan bears direct responsibility in these cases – though she was part of senior management when they occurred. However, there has been growing disquiet in political circles at the gross inadequacy of the responses of the Garda leadership to what has been a torrent of disturbing revelations.

Until now, the Government had continued to express confidence in the Garda commissioner – in a way that often seemed impossible to fathom. “What dose she have on them?” one opposition political figure asked Hot Press privately.

In the end, the most likely answer is nothing at all. Fine Gael is historically the party of law and order. Its grandees have traditionally placed far too much trust in the Gardaí, resulting – for one – in the brutal excesses of the Heavy Gang, which operated with apparent impunity within the Gardaí in the 1970s, while Fine Gael’s Patrick Cooney was Minister for Justice.

And so, even as the scandals mounted, the government were reluctant to make a move – first against Callinan and latterly against his replacement.

"As she (Nóirín O’Sullivan) said in her statement,” the Taoiseach Leo Varadkar stated today, “her decision to retire is made in the best interests of An Garda Síochána and ensuring that it can focus on the extensive programme of reform that is now under way."

Did O’Sullivan jump or was she pushed? One view is that, so consistent and relentless has been the tide of revelations that only someone of super-human obstinacy could have resisted the pressure to go. The other is that the Government had simply grown so tired of the distractions involved in shoring her up that they would have been mad not to indicate to her what they wanted her to do.

While one must have sympathy with any individual fighting to hold onto her job, while caught in the middle of bruising events over which she had little control, she is gone now – and it is doubtless for the better. The big question is: who is next for the poisoned chalice? Answers on a Breathalyser Report Card, please…