The point is that between the UK and Ireland there is a CTA, common travel agreement. Yes there is, and it has existed since long before the EU or its predeces

The point is that between the UK and Ireland there is a CTA, common travel agreement. Yes there is, and it has existed since long before the EU or its predecessors existed. This means frictionless border crossing between the Republic of Ireland and Northern Ireland. No, it means that citizens from either side are allowed to cross the border by default. Production of some basic ID documents may still be required. Checks may still be (and sometimes are) carried out. And the whole thing is based on essentially a long-standing gentleman's agreement and explicitly does not create binding legal obligations. In short, the CTA does not require a completely frictionless border and never has. Indeed, that could not possibly be its effect, because its provisions only cover British and Irish citizens. If the UK leaves the EU then goods from the UK cannot just be moved into the Republic of Ireland if there is no join customs agreement. It's a lot more complicated than that, but yes, the existing provisions for moving goods across the border are governed by EU mechanisms, including the Customs Union and Single Market. So now you have to introduce a hard border with the RoI which goes against the Good Friday Agreement. And at this point I ask you much the same question that I have asked others in this discussion: What specifically constitutes the "hard border" that is required, and in what specific way(s) do any associated processes or infrastructure contradict the GFA? If you don't understand the relevance of the GFA then you should read up further on or and the Troubles that preceded it. Please don't be patronising. It is both rude and unconstructive. The GFA is widely cited by advocates on one side of the Brexit debate as some form of barrier to some possible outcomes, yet it appears that many of those people haven't actually read it and think it says things that it doesn't. It is not unreasonable, when someone introduces it as a new factor in a discussion that was previously about matters of sovereignty, to seek clarification about why they think it is relevant and whether their arguments have any more substance than a lot of the other ones we see referring to the GFA.