You can't be a separate country if you can't _ever_ enforce borders.
Well, there's no reason for the UK to enforce any border between NI and the Republic as we're both in the EU and we also operate the Common Travel Area which has been going for nearly 100 years.
But you see Maf, the whole point is that Ireland IS actually one country. It's an island and it's basically one nation, artificially divided. The Good Friday Agreement addressed that in a way that was satisfactory to most of the people of NI and the Republic. It removes obvious signs and infrastructure that suggest separate countries and it allows people to choose to be Irish or British. Together with membership of the EU, it was the nearest way for Nationalists to feel they lived in Ireland, and for Unionists to feel that they were still living in the UK. Very importantly, it acknowledged the right of the Irish population of NI to legally and legitimately be recognized by the British government as Irish.
It's a bit surreal, but it's worked until now. Left as it was, another thirty or forty years would probably have seen a natural drift towards some form of united Ireland but it's not right that it should come about at this time nor in this way.
Watching Varadkar with Boris today was revealing - Varadkar is just in a different class.
Vardakar and Simon Coveney are a credit to Ireland really in how they've handled Brexit. And in fact, the whole of the Irish parliament and the opposition has been superb in their solidarity and standing behind the government in the best interests of Ireland. We've had some real old gombeen men as we call them in Irish politics over the years but Varadkar and Coveney are proper statesmen.