Foreign Policy Essay

How Would Brexit Affect Counterterrorism?

By Richard English
Sunday, August 25, 2019, 10:00 AM

Editor’s Note: As Brexit looms, predictions of chaos dominate the headlines. Brexit’s critics have expressed fears of financial disaster, the collapse of key services and risks to the security of the United Kingdom. Richard English of Queen’s University assesses how Brexit might affect U.K. and European counterterrorism. He argues that counterterrorism cooperation is likely to continue and that, on this issue at least, the danger of Brexit to the United Kingdom is minimal.

Daniel Byman


The emergence of Boris Johnson as prime minister of the United Kingdom has begun a new act in the Brexit opera. But one of the less-discussed issues in this turbulent plot is whether the music will move us toward a violent end. In an era still preoccupied with post-9/11 terrorist violence, there has been relatively little consideration about whether Brexit may cause major security problems for the European Union and the United Kingdom.

Some former U.K. security figures have welcomed Brexit as a way of ensuring that the country can gain stronger control over its borders and its security, allowing it to better guard against terrorism; others have argued that Brexit poses challenges through the risk of fracturing the security relationships that currently exist between the United Kingdom and its EU allies.

The likely reality, though, is that counterterrorism security is one of the few areas in which Brexit will make comparatively little difference. Anti-Western jihadists in al-Qaeda and the Islamic State have shown relatively little interest in Brexit—reasonably enough, from their narrow point of view. A squabble between some of their European enemies makes little difference to them in terms of judging which countries should be targeted with jihadist violence. More importantly, the capacity of the United Kingdom and its soon-to-be-former EU neighbors to counteract such jihadist violence is unlikely to be greatly damaged.

The United Kingdom’s most significant and successful international collaboration on counterterrorism is not related at all to the European Union but, rather, lies in the Five Eyes community of the United States, United Kingdom, Australia, Canada and New Zealand. Those global connections will remain unaltered by Brexit, and they demonstrate that the United Kingdom can develop successful coordination of counterterrorism relationships outside a supranational body such as the European Union.

Moreover, existing counterterrorism cooperation even between EU countries has not been conducted through the European Union. As Javier Argomaniz has pointed out, law enforcement and intelligence agencies in Europe even now see terrorism primarily through national lenses, and cross-country coordination of such efforts has not involved the European Union as the first point of contact or reference. So relationships between the U.K. Security Service (MI5) or Secret Intelligence Service (MI6) and their respective counterparts in EU countries can continue to operate on the basis of direct contacts between national agencies.

That neighbors with shared terrorist enemies can and do cooperate beyond the EU network is reinforced by another largely undiscussed reality: Neither Brexiteers nor Remainers can afford to allow their politics to be held responsible for greater risk of terrorist attacks in Europe. One of the few things the very divided United Kingdom and fractured European Union can agree on is that counterterrorism coordination must continue beyond Brexit and that effective measures and relationships must be sustained, refined or improved in order to protect citizens’ safety. Every member state within the European Union, and the EU itself, shares this goal.

There will be risks if a hard Brexit were to occur immediately, in terms of the need for speedy implementation of replacement mechanisms for those that would have become lost. A new relationship with Europol would be required quickly, for instance, especially in relation to any ongoing threats such as those involving jihadist militants. Similarly, care would need to be taken to ensure the continuance of smooth extradition between states.

But the rapid adjustments are likely to be secured, and for one very important reason: Neither Brexiteers, nor Remainers, nor governments across Europe want there to be a terrorist attack that can be pinned in part on Brexit having caused a lack of preventive interstate coordination. Yes, a hard and sudden Brexit would generate challenges requiring fast responses, but the relevant states have the capacity and the imperative to produce them.

Brexit has also raised questions about terrorist threats that don’t involve continental Europe. The number of paramilitary groups in Northern Ireland has been rising since 2007, and one group assassinated a journalist in Derry in April. It is true that Brexit has reinforced political polarization between (mainly pro-Remain) Irish nationalists in the North and (more Brexit-favoring) Ulster unionists. But it would be wrong to exaggerate the extent of the change in terrorist threat any time soon. Dissident Irish republicans represented an enduring, localized and occasionally lethal threat before 2016, and that is what they still represent now. Despite ongoing political acrimony in Northern Ireland, most people on both the nationalist and unionist sides of the community prefer to endorse nonviolent politics, and the support for Dissidents will remain small, as is shown by the negligible levels of support secured by their political representatives.

It is true that border infrastructure would present targets for such violent actors if a harder border between Northern Ireland and Ireland were introduced, but it is not true that the conditions exist for the kind of large-scale violence that occurred in the North during the 1970s and 1980s. The power relationships between unionists and nationalists in Northern Ireland, and the relationship of nationalists to the state, its institutions and its economy, have all been decisively changed since those bloodstained years. Whether in terms of political power-sharing in Northern Ireland, the ameliorative effects of fair employment legislation, or police reform, nationalists in the North now find Northern Ireland to be a considerably fairer polity than it was during the worst years of the conflict that emerged in the 1960s.

Indeed, one of the ironies of the Brexit drama has been that it has reinforced the possibility of the United Kingdom disintegrating without separatist violence. In the 2016 EU membership referendum, the majority in Scotland voted to remain in the European Union. The disjunction between this preference and the United Kingdom’s departure from the European Union has reignited the possibility of Scottish secession, which had receded with the defeat of the separatists in the 2014 Scottish independence referendum. Similarly, while Irish nationalists in Northern Ireland have understandably resented the prospect of being dragged out of the European Union against their wishes (and on the basis primarily of English votes and Democratic Unionist Party backing), they have not shifted their allegiance toward violent Irish republicanism. If a border poll in Northern Ireland were to produce a pro-Irish unity majority, then it would have been Brexit, rather than the Irish Republican Army, that would have brought this about.

Brexit has already caused huge division in the United Kingdom, and that fracture shows little sign of healing any time soon. But one of the crucial aspects of this political opera is the overwhelmingly irenic dimensions of the rupture. Brexit has been acrimonious but far less violent than previous, similar nationalist movements. It will not be allowed to generate significantly greater risks from terrorism. And, if it does help to initiate the end of the United Kingdom, then it will have been divisions within and between constitutional parties—rather than the acts of terrorists—that turn out to have changed history.