Whether one is an enthusiastic European or not, the truth about Brexit from a national security perspective is that the cost to Britain would be low. Brexit would bring two potentially important security gains: the ability to dump the European Convention on Human Rights—remember the difficulty of extraditing the extremist Abu Hamza of the Finsbury Park Mosque—and, more importantly, greater control over immigration from the European Union.
One loss that would result from Brexit and which has been cited by Theresa May, the Home Secretary, as a reason for her supporting Britain’s continued membership of the EU, would be the European arrest warrant. But its importance has been exclusively criminal and few would notice its passing.
Britain is Europe’s leader in intelligence and security matters and gives much more than it gets in return. It is difficult to imagine any of the other EU members ending the relationships they already enjoy with the UK. Furthermore, counter-terrorist and counter-espionage liaison between democratic allies is driven as much by moral considerations as by political ones. If a security source in Germany learns that a terrorist attack is being planned in London, the Bundesamt für Verfassungsschutz, Germany’s domestic intelligence service, is certainly not going to withhold the intelligence from MI5 simply because the UK is not an EU member.
In addition, though the UK participates in various European and Brussels-based security bodies, they are of little consequence: the Club de Berne, made up of European Security Services; the Club de Madrid, made up of European Intelligence Services; Europol; and the Situation Centre in the European Commission are generally speaking little more than forums for the exchange of analysis and views.
With the exception of Europol, these bodies have no operational capacity and with 28 members of vastly varying levels of professionalism in intelligence and security, the convoy must accommodate the slowest and leakiest of the ships of state.
