Ultimately it was more complicated then the politicians expected. There's a lot that went wrong, but Northern Ireland is the one thing that should've been figured out before this was even started - and not just "hand waved" to figure out later. It either needs to be separated from Ireland and unified with the UK, or separated from the UK and unified with Ireland. The politicians wanted to use nonexistant technology/magic to pull it off, but ultimately with the UK no longer part of the EU Northen Ireland cannot functionally be part of both the EU and UK trading blocks - and grocery store shelves are going empty trying to do so.
There are only four possible resolutions to this problem:
a) ireland leaves the EU and joins the UK trading block
b) the UK rejoins the EU and unifies the trading block.
c) Northern ireland splits from the UK and rejoins the EU trading block either as it's own country or as part of Ireland
d) repeatedly burn through PMs who fail to resolve this deadlock while things continue to fall apart.
Ehhhhhmmmm...I'm going to go with "no". If you ask me, people like Johnson and Farage never expected to actually win the brexit vote in the first place. That's why the first negotiators were utterly unprepared (there was this photo of the first meeting: the EU negotiators had a couple maps and some laptops, the UK negotiators didn't even have a notebook with them), the first minister turned out to be a remainer and the investigation of the feasibility was non-existant (most striking that I remember was Dominic Raab expressing that Dover was far more active than he had initially thought. And that guy was secretary of state for Exiting the EU).
Yes, Northern Ireland was a problem. But not because of its location. After all, Gibraltar voted like 99% remain and last I heard they were happily still being part of the UK. Following
MORE EU regulations than before brexit, but nobody's complaining.
No, NI is a problem because their local political group (DUP) is diametrically opposed to anything the EU wants or needs
AND the UK government needs their support to stay in power. That's also why I said I was skeptical of Sunak's deal (Windsor framework). This whole stuff of "red lanes and green lanes" isn't new. Fuck...it was proposed by the EU back when...erm...either May or Johnson still ran the show. And there's only a small reason it might play out different:
The deal consists of asking the NI population to vote on it's implication.
DUP has already lost influence to Sinn Féinn but still holds the de factor power in the region (AFAIK). This part of the deal is a poisonous gift to them, and I think they're aware of that. They can't really rally against the deal (or framework? I can't tell the difference) because it goes directly against what their voters want. But the population in Northern Ireland have no reason NOT to vote on its implication: those who want a reunited Ireland see it as an opportunity and those who want the economic profit as well. The only ones against it are the DUP itself, because they're treatened to become irrelevant to Sinn Féinn.
It <Northern Ireland> either needs to be separated from Ireland and unified with the UK,
Hmm...sorry if I'm being condescending, but this part doesn't make sense: NI never was
not unified with the UK in this ordeal. And that's the entire pickle: the UK always treated NI as part of the UK. For good reason, but they forgot they can't just make up their own laws (or rather: standards on things like food) and not expect border checks. And they can't do border checks either because that upset the locals (the good friday agreement was heavily fought over and won't be dismissed).
I'm presuming you meant to write "there should be a strict border between Northern ireland and the rest of ireland" there, correct?
As for your options...here's my opinion on these:
a) ireland leaves the EU and joins the UK trading block
Yeah, I've heard that suggestion. I don't often get physically angry, but that was a time it happened. The fucking AUDACITY!
"Hey guys: we're lowering our food standards, and we're not going to hold border checks. If it bothers you that lower quality goods might enter your market, just surrender the rest of Ireland to us, mkay?
"
b) the UK rejoins the EU and unifies the trading block.
the most likely to happen. But not in the near future. I have a few ideas on why labour isn't jumping on the bandwagon, but sooner or later someone is going to have to face up to the fact that it was a collossal failure and the best course of action is to rejoin. Probably without all the benefits the UK had as a EU member.
c) Northern ireland splits from the UK and rejoins the EU trading block either as it's own country or as part of Ireland
This would be my gut response to a). The DUP will fight it hell or high water, but if Sunak's gambit pays off they might become irrelevant. For as far as I can tell, Sinn Féinn isn't as reckless as the tories so I don't think it'll be a near future solution. But depending on things play out, I consider this the second most likely outcome.
d) repeatedly burn through PMs who fail to resolve this deadlock while things continue to fall apart.
It's not a deadlock. It's economically worse than within the EU, but the UK has the media on its side. It's only after Truss's resignation that the major ones even bother criticizing brexit in the first place (2+ years after the fact). Arguing in the "brexit benefits" thread ended up feeling like swimming against the river flow. For every economic argument I brought, the proponents repeated some sort of "the EU is a dark, evil, bureaucratic empire" statement. Not sure where these guys are now, but at best they're having doubts. But it's more likely they just blame the EU for their misery. And as such, rather have the economic downside.
So..."burn through" might be not the wrong way to put it, but there'll probably be some status quo's and follow-ups of prime ministers before someone dares to bring up the idea of joining the EU (and get politically burnt for that, most likely).