When I was a boy in the late 1980s I remember visiting Derry with my family. We were on holiday in Donegal and somehow decided to take a day-trip to the north. It was an unusual thing to do at that time, because the troubles were still raging. I remember the tension of waiting in the queues of cars at the border point, the armed soldier who asked us questions, the barbed wire, land rovers wrapped in metal cages, the fact that nobody smiled.
Today the Northern Executive generally does its best to ensure that everybody receives equal treatment, while the causes of past conflict are tackled at source. A large number of important trade links with the north have been established. Many agricultural goods cross the border for processing before crossing back for sale. An open border is worth millions to both economies. Things are still not perfect, but they are better for people now than they have been for many years.
Brexit has thrown up huge challenges to the fundamentals that brought this prosperous time. It is imperative that whatever suggestions are put forth are realistic and balanced. The question of whether or not Northern Ireland can remain a member of the EU, as proposed by Sinn Féin's Matt Carthy, is a very tricky one.
If Northern Ireland could find a way of staying in the EU as a stand-alone entity that would be great, but with a British currency, systems of healthcare, education, justice and public administration, this would be extremely difficult to manage. There is already enough division at the moment without this complication and expense.
Brexit is not an opportunity to push for reunification. We've just had the longest interval of peace since partition was introduced and it is imperative that everybody remembers how hard it was to achieve. The north still has a determined unionist majority who may never agree to Irish reunification. Meanwhile any attempts at introducing it could reignite the troubles.
It is too easy to forget all that led to to the Good Friday Agreement in 1998. So much carnage, so much pain. And for what? Each outrage only hardened the hatred one side felt for the other, until they all reached breaking point and sued for peace. Coming as it did, when a sense of relief that it was over at last, the Omagh bombing was the final straw. By then, even hardliners were so tired of war that they were willing to suspend their objectives and work as hard as they could to achieve a lasting peace.
With the tentative trust that has grown within the EU's open-border community, people have expanded their worldviews. Nowadays you can find unionists visiting the south on their holidays while southerners who grew up on a diet of negative stories about the north, realise at last that it is a beautiful and welcoming place.
Younger generations have grown up without fear and without restrictions. In all but name this island is currently united. The British vote to leave the EU threatens to shake our present unity. As old territorial urges re-emerge, a fog of amnesia could erase the foundations of peace. In the context of world history, where two distrustful groups of people must live side by side, it doesn't take much to shatter peaceful co-existence.
We need to find a solution that allows the Northern Executive to maintain its close links with the south while remaining a part of the UK. The current arrangement is mutually beneficial and should to be protected. The Westminster government is not concerned enough about the impact of Brexit on Northern Ireland and is determined to close UK borders. But with many international companies already thinking of leaving Britain, the financial implications of Brexit will soon hit home. The UK could soften its stance much sooner than expected.
Meanwhile negotiators have to be strong and determined to protect the best interests of the north. The UK government should to be told to forget its paranoia and think about helping its people instead of hindering them. If it insists on filtering out those it perceives to be unwelcome, then controls at crossing points to mainland Britain are the only realistic option. Reverting to manned border controls would destroy the open trade relations that are bringing prosperity and maintaining peace both north and south. That is something none of us want to see happen.