It is commonplace to talk more about the economic impact, but a British exit from the EU (so-called Brexit) could lead to a variety of political disasters.
First, Ireland
This would be the country most affected by Brexit, due to the impact it could have on the Ulster peace process. The Good Friday peace agreement of 1998 had a clear European dimension. Its design and implementation would have been very much more fraught had the Republic and the UK not both belonged to the EU. The European Commissionhas invested a great deal of money in intra-EU projects. And the border between the six counties of the north and the Republic of Ireland has become blurred to the extent of virtually disappearing (outside Schengen, a system to which neither country belongs). Brexit could force the border to be reinstated, and destabilise a peace process that has still not healed the wounds between Protestants and Catholics, or advocates of maintaining the union with Great Britain and joining the Republic. Moreover, Ireland and the UK form an authentic single labour market, which may be jeopardised. Irish citizens resident in the UK will be able to vote in the referendum on 23 June, and they will cast their ballots in favour of staying in the EU. This is without even considering the trade between the two. A recent academic study speculated that a united Ireland in the eurozone could add 30 billion euros to its combined GDP. Although the study does not deal broach the subject, a divided Ireland, with the south in the EU and the north outside, could produce the opposite outcome.
Secondly, Scotland
Here perhaps the situation will not be as dramatic over the short to medium term. It has been said that if the English decide to leave the EU, the Scots may choose to remain, fracturing Great Britain with a new independence referendum. The former Conservative prime minister, John Major, believes that there is a “considerable probability” of the Scots wanting to leave the UK in order to remain in the EU. But many Scots are more cautious and want to avoid having to choose between London and Brussels (which is not particularly popular in Scotland either). They would have to negotiate their entry as a new member state and commit to adopting the euro in the future, without the existing British opt-out; the euro too in unpopular among the Scots, more than 60% of whose trade either already goes to the rest of the UK and less than 20% to Europe. The Scottish nationalists, now advocates of independence and with an absolute dominion of the region/nation’s politics, do not yet want a second independence referendum that they could again lose, as in 2014. They prefer to wait and see what the outcome of the Brexit poll is and, if the leave side emerges victorious, wait and see where London’s subsequent and complicated negotiations with the EU lead to in terms of a new status on the outside. But the issue is on the table over the medium and particularly the long term.
Thirdly, the political dimension of the EU
A victory for Brexit would be a blow to the internal and external reputation of the EU, the heft and credibility of which would be damaged. This is not only because it would create a precedent for other exits, although to an extent such a precedent has existed since Greenland chose in a referendum in 1985 to leave what is now the EU, albeit remaining as part of Denmark. It is also because the UK is an essential element of the EU’s foreign and security policy, even if it has not fully supported it. Deprived of the UK’s armed forces, the EU’s joint military capacity would lose a great deal; likewise, without its foreign engagement. Ironically, the day after the Brexit referendum the 28 member states will meet in the European Council to, among other things, agree progress towards a common defence policy, albeit involving relatively few, using what has come to be called “enhanced cooperation”, something to which London may sign up if Cameron succeeds in winning the referendum. Although (as yet) this is little mentioned in public.
Furthermore, the calls to democratise the EU may become weaker. With their respect for institutions, the British have called to preserve and strengthen, among other things, the role of national parliaments. They believe in Westminster and in their system. They have been very active in this type of demand, although they persist in the illusion of their own national sovereignty.
This is without raising the subject of Gibraltar, which is an EU territory, albeit with a special status, and would cease to be so in the event of Brexit. This would not however cause the Gibraltarians (despite concerns voiced in a report by Gibraltar’s prime minister, Fabian Picardo) to alter their desire to remain in the UK if the latter opts to leave the EU, however much its colonial situation would then be even more of an anachronism.
It is better that the British do not leave the EU. From the political perspective, there is not a single advantage for the rest. Nor for them.