I agree that breaking the Northern Ireland protocol for the sake of EU trade was a mistake, a bad mistake, but it needn't have been a consequence of Brexit. It would have been far better, and perfectly practicable, to have trade between the North and the Republic on the same terms as the rest of the UK/EU trade
But the Republic is in the trading block? What are you suggesting here? The UK adopts EU terms, or ROI severes its deal with the EU to trade on UK terms?