Will remaining in the EU help secure the peace that has mostly held in Europe for the last 70 years better than leaving?
If you look back across European history since the middle ages, you will see it has been dominated by wars with many of them between the Germanic Holy Roman Empire and it successors fighting France & its allies for domination of the Continent. These wars have often dragged the United Kingdom into the conflict on side or another. In the last 300 years, we have had the War of Austrian Succession (1740-1748), the Seven Years War (1756-1763), the French Revolutionary Wars (1793-1802), Napoleonic Wars (1803-15), the Franco-Austrian War (1859), the Franco-Prussian War (1870-71) and the two World Wars (1914-18 & 1939-45).
Since then, since the founding of the European Coal and Steel Community[i] (the precursor of the European Economic Community) in 1951, Europe has been mostly at peace. More than that, the European Countries that were under dictatorships have nearly all turned into democracies and those that haven’t already joined the EU are queueing up to get in.
This is not all down to the EU but, especially in the Balkans, it has been the EU that has been in the forefront of developing democracy, encouraging trade between former enemies, helping to find diplomatic solutions, defusing possible issues that could lead to fighting. A good example of this is how, by both being in the EU, the United Kingdom & the Irish Republic have defused border tensions during the troubles in Northern Ireland and helped bring about a stable peace to allow leaders from both sides to discuss political solutions.
I am not suggesting that this extraordinary period of peace in Europe will end overnight if the UK leaves the EU but, if our leaving the EU damages it as much as some suggest it will, then there is a chance it will fall apart and the old enmities will re-surface. If those enmities spill over into armed conflict, then. just as in such European conflicts in the past, the UK could well be drawn in to the fighting.
This 70-year peace in Europe (an unprecedented period) is too precious to throw away or even risk throwing away because some in the UK cannot get their head around cooperation & shared sovereignty that benefits us all.