British Prime Minister David Cameron has lately begun to speak out about the importance of European Union (EU) membership for the United Kingdom’s security. That is probably the most compelling argument for remaining in the EU that Cameron could present to British voters ahead of a referendum on whether the UK should withdraw.
But is Cameron, who has promised to hold the vote by the end of 2017, making the security argument too late in the day?
Many claim that, because Nato ensures the UK’s defence, a British exit from the EU (“Brexit”) would not undermine the country’s security. But security and defence are not the same thing. True security entails the expectation that a country will not have to call upon the defence alliances to which it belongs – and that is what membership in the EU, as it stands today, provides.
Between World Wars I and II, America’s defence did not depend on its membership of the League of Nations. But the country’s decision not to join the League of Nations – based on sovereignty arguments much like those now being used to promote Brexit – led to the League’s collapse, severely weakening US security.
Today, the UK enjoys an unprecedented level of security. Despite instability and violence in countries like Ukraine and Syria, the UK does not face even a remote strategic threat. And EU membership virtually guarantees co-operation against the tactical threat posed by the Islamic State.
A Brexit may well set in motion a cascade of events that could profoundly undermine that security. Eurosceptic and nationalist parties, not to mention some on the extreme left, would be strengthened across the EU. And while one cannot doubt the democratic and pro-Western credentials of most UK Eurosceptics (though one can doubt their wisdom and strategic sense), the same cannot be said of many of their counterparts on the continent.
Consider Marine Le Pen of France’s far-right National Front party, whom Brexit could help propel to victory in the 2017 presidential election. Le Pen, whose popularity has been driven largely by resentment of Germany’s growing influence, is openly hostile to the euro and the EU.
With Le Pen in power, a major EU and Nato member would be pursuing a profoundly anti-Western foreign policy. Her defence of Russia’s aggression in Ukraine, for example, suggests that she would block any form of resistance to President Vladimir Putin’s adventurism, which is threatening Nato’s eastern flank.
With or without Le Pen, Brexit could spur a “flight to nationalism” across Europe, as countries react to rising chauvinism among their neighbours by electing the domestic brand.
Political conflicts would then intensify and become increasingly difficult to resolve, with the return of vicious national enmities, unseen in Europe since 1945, confronting the EU with an existential crisis from which it would not be easy to recover.
In fact, such forces are already on the rise. The trend began, somewhat unexpectedly, in Western Europe and is moving eastward.
So far, the effect of nationalism has been most potent within countries, in places like Scotland and Catalonia, rather than among them. But, triggered by Brexit, that could easily change, with countries turning against one another to protect their perceived interests.
In addition, as many observers (including Cameron’s first foreign secretary, William Hague) have pointed out, Brexit could give a huge boost to Scottish nationalism; the breakup of the UK would further weaken Britain’s security.
Beyond Europe, Brexit would estrange the UK from the US, where presidents from both major parties, beginning with Dwight D Eisenhower (who also served as Nato’s first Supreme Commander), have touted European integration. By thumbing its nose at so fundamental an American interest, Britain would almost certainly undermine what remains of the bilateral “special relationship” that UK governments have cultivated since Winston Churchill’s premiership.
Thus, there is hardly a dimension of Britain’s security that would not be devastated by Brexit. One can only hope that this point will get the attention it deserves in time to influence the outcome of the referendum. - Project Syndicate

- Jacek Rostowski was Poland’s minister of finance and deputy prime minister from 2007 to 2013.