Wednesday's letter by Irish Ambassador to the US Michael Collins, to the US Subcommittee on Permanent Investigations, set out Ireland's stall on the tax haven issue, but failed to achieve its intention if it was designed to repair damage to our reputation.

Senator Carl Levin, the Democratic chairman of the subcommittee, and his Republican colleague, John McCain, didn't hold back when responding, saying Ireland's dealings with Apple met a "common sense" definition of tax haven.

The details over whether the Apple subsdiaries at issue are tax resident here, and the linked issue of whether the subcommittee is doing a valid exercise when it divides tax they pay by the profits they make and attributes the low effective tax rate that thereby arises, to Ireland’s supposed tax haven status, are unlikely to be the kind of stuff that will capture the public’s imagination.

Irish politicians may be frustrated by what is happening there, but most likely at the same time they will smile ruefully at the antics of their US counterparts.

As Collins put it in his letter, the focus of the US subcommittee is US tax reform, something in which Ireland has no role.

No doubt, however, it is easier for the US politicians to rubbish Ireland’s reputation, than it is to address the complex issue of corporation tax reform.

In Derry, on Thursday, the co-founder of Apple, Steve Wozniaki, weighed into the debate, saying the international tax system was corrupt because it was biased in favour of powerful corporations and against "the little guy".

He said he understood why individuals were shocked that rich companies could minimise their tax bills whereas workers were taxed on everything they earned. The system was the way it was because the large corporations have the power and the money to make sure politicians create a world that enhances the corporation, said the man who founded Apple along with the late Steve Jobs.

That sounds like a common sense view of the world. So too is the view that if the global tax regime is to be improved, it will have to be done by way of international co-operation. Mud-slinging, however, will always be a temptation.