First of all, Montana enjoys 10th Amendment dual-sovereignty, just like every other US state.
But second, you seem to be asserting that the other involved sovereigns have no right to hold Ireland to the commitments it agreed to when it signed treaties. How is that supposed to work? Are treaties now just lies of convenience?
The European Union isn’t sovereign. It likes to pretend it is, but it isn’t.
> Are treaties now just lies of convenience?
They’ve just about always been just lies of convenience. Think Molotv-Ribbentrop pact. Or the START treaty. Or the Iranian nuclear deal. Or the Treaty on Conventional Armed Forces in Europe, which is dead as of yesterday, because NATO suspended it too.
> The European Union isn’t sovereign. It likes to pretend it is, but it isn’t.
I'm going to assume you're misinterpreting rather than trying to be disingenuous, but I was obviously referencing the nations Ireland signed the series of treaties starting with the Treaty of Lisbon (which Ireland signed in 2009).
France, Germany, etc. are perfectly within their rights to hold Ireland to the agreements it made.
> They’ve just about always been just lies of convenience.
Your examples are proving the opposite of what you appear to think they do. The US would be a much better example of what you mean, but that just demonstrates that nobody currently wants to take the US on.
In any case, Ireland is perfectly free to exit the treaty normally if it chooses. England showed them how.
But second, you seem to be asserting that the other involved sovereigns have no right to hold Ireland to the commitments it agreed to when it signed treaties. How is that supposed to work? Are treaties now just lies of convenience?