The programme is there for the convenience of the US. Would they allow Ireland to operate a corresponding facility on US soil?
(The popularity of that airport for CIA torture flights also doesn't help the case, even if not directly linked)
(The popularity of that airport for CIA torture flights also doesn't help the case, even if not directly linked)
Let's talk about Toronto or Vancouver to set aside CIA whatever. What particular convenience does it provide for the US government to do it there vs on the US side? AFAICT that would save the airline that brought a person who got denied a bit of trouble - vs having to take them back to their departure airport - but not be a particularly huge convenience or burden for either government at a higher-up level.
It reduces legal accountability (I know the US courts have generally exempted border operations from the constitution anyway, but that interpretation could change in the future) and makes it easier to prevent people from e.g. landing and claiming asylum (yes there are measures to penalise airlines and oblige them to return passengers, but they're not always fully effective). More subtly it means there's less pressure to have reasonable border rules, since turning someone away before they board is lower-stakes. And having an official, pseudo-law-enforcement presence in a country is valuable almost in itself.
Well maybe. What happens when you try to exercise that right? If it turns out that those US border officials falsely imprisoned you (under Canadian law - if the Canadian courts are even willing to hear the case), what consequences will they face?
FWIW, I recall reading that the program in Canada is reciprocal, and it is simply the case that Canada hasn't decided to operate any corresponding facility in the US.