The EU showed that it wasn’t willing to negotiate in good faith when it used the Irish border as a pre-condition to be solved before trade talks began. At that point, if the UK Government had a backbone, it would have walked away. When the UK Leaves the EU, the EU will have to erect a hard border between The Republic of Ireland and Northern Ireland. That is how it works. Northern Ireland is sovereign territory of the UK and is bound by the referendum of June 2016. When the UK leaves, then Northern Ireland will leave too. The EU will put up a hard border between it’s members territory and the UK. The UK do not want a hard border, and The Republic of Ireland don’t want a hard border. It is for the EU to find a solution. The Republic of Ireland should be petitioning the EU for a solution to it’s problem not placing the blame solely on the UK Government.