Saw you need one for Italy. Do you think it is a good idea to get one for Ireland?
You won't need it. It's basically a translation of your US license, and since they speak English there it is unnecessary.
It's not required in any English-speaking country.
Well...to be technical, Yes, per the International Conventions dating back to 1949, you do need the IDP. While it is certainly a translation, it is also documentation that what you show as a license, is indeed a valid license in your country. In any country, English speaking or not, if someone is willing to accept your DL only, great. In English speaking countries, you certainly have a better chance of communicating and convincing them your license is proper, but you have no guarantee. In the end, you likely will have no problems, but for $15 and a few minutes of your time, it might be considered cheap insurance.
According the the US Embassy in Dublin's website, Americans are allowed to drive in Ireland using only their US drivers license. The Conventions of 1949 refer to visitors to the US FROM Ireland. The website specifically states that visitors TO the US must have International Driving Permits. There is no such statement regarding visitors to Ireland.