In following the ongoing Brexit drama, it seems everything is resolved except the question of the Norther Irish border, which is very difficult indeed to solve.
Idea: draw a new border that splits Northern Ireland into two pieces of roughly 60:40 in size (this is based on a guesstimate of what the proportion of both sides are; adjust if this is inaccurate). Get all nationalists to the 40% side, all unionists to the 60% side. The 40% side joins Ireland and becomes one of its provinces; the 60% side stays in the UK. Then implement a hard border. There'll be mechanical problems to this of course (e.g. it would necessarily involve a lot of people having to buy new houses) but those should be temporary. Meanwhile if this works, it would separate the two infighting populations and hopefully solve the problem permanently.
Such a solution would not necessarily have to involve forced population transfers - one could choose to stay put, and then agree to identify with & abide by the laws of the country one ends up in (whichever that is).
I am wondering if can plausibly resolve the conflict. If yes, has it been seriously discussed? If no, why not?