Irish invade Northern Ireland but in a good way.

As an interesting side effect of the strength of the euro against the pound Irish shoppers have been swarming into Northern Ireland in order to buy their weekly shop. The BBC interviewed one woman who was getting expensive dental treatment done in Northern Ireland for the same reason.

It isn't good news for the Irish shops but I can't help feeling good about such ordinary interactions between Ireland and Northern Ireland.

This always happens in some shape or other. Over the decades there has been price difference in things like food, petrol, cigarettes and alcohol which lead to people seeking bargain on one side of the border or the other. Even the IRA got in on the act smuggling goods either side of the border to sell on the black market. Now with the Sterling getting weaker the border counties on the south side are going to feel the pinch.

Your point is well taken though and reinforces a point I often make. Open trade does help to break down social and political boundaries. I would look at the EU as an even larger example of what you cite here.