On Sunday, the Work and Pensions Secretary, Iain Duncan Smith, opened up a new flank in the ‘Brexit’ argument: that staying in the European Union (EU) would leave us vulnerable to Paris-style terrorist attacks. This followed several days of briefing from Number Ten and other cabinet ministers that the UK would be both ‘safer and stronger’ staying in the EU.

So who is right? Broadly, the issues can be broken into three:

Border control

IDS’ argument rests on the idea that our participation in EU free movement laws leaves us unable to prevent potential terrorists from arriving here. He said ‘this open border does not allow us to check and control people that may come and spend time’…‘We’ve seen what happened in Paris where they spent ages planning and plotting so who’s to say it’s not beyond the wit of man that those might already be thinking about that.”

Is he right? The answer is, mostly ‘no’, but it depends what he means. There is an issue with the porous nature of some of Europe’s outer borders – countries like Greece, Hungary and Croatia simply do not have the infrastructure to process the number of refugees that are now arriving, so of course there is a chance that some dangerous people might slip through the net and subsequently find their way to the UK. But to go from here to arguing that the UK would be safer outside the EU is a leap.

For a start, whilst we are signatories to free movement laws, that does not mean we have an ‘open border’. The UK is not bound by the so-called ‘Schengen agreement’ – Europe’s internal borderless area; and we are not bound by EU legislation on border controls, or non-EU immigration. Indeed it was actually a Conservative government that negotiated the right for the UK to retain responsibility for its own border control and have flexibility to adjust its immigration policy in response to circumstances. As anyone who has returned from a holiday abroad knows, our Border Force officers conduct checks on EU/EEA travellers crossing UK ports of entry, as well as British citizens and non-EU/EEA nationals.

The problem is not our inability to screen new arrivals and/ or refuse entry on grounds of public safety, it is that often we lack the information we need to know whether or not someone is dangerous. And this is where the argument for ‘in’ looks stronger. Because our membership of the EU gives us access to certain sources of information which support border security processes. The Schengen System database might sound like something from a John Le Carre novel, but it is a vital tool in giving UK law enforcement and border agencies access to real-time information about wanted or missing people and public security threats.

Of course, the EU is by no means the only, or most important, game in time for sharing intelligence. The UK can and does have highly effective intelligence-sharing arrangements with non-EU countries. The ‘Five Eyes’ agreement with the USA, Canada, Australia and New Zealand is arguably a deeper relationship than that between the UK authorities and the EU. Moreover, every intelligence officer is aware that any network is only as safe as its weakest link and while many UK security officials and police officers have good relationships with their French, German and Dutch counterparts, they may be less willing to trust their opposite numbers in some other EU states, particularly those with high levels of corruption and organised crime infiltration.

Police and judicial cooperation

Crime does not respect national borders. 90 per cent of heroin consumed in the UK is grown in Afghanistan; the UK has suffered repeated cyber attacks from organised criminal groups operating out of Russia and China; human trafficking, by definition, is a globally coordinated practice. So ensuring our law enforcement agencies are able to work with their partners in other European countries matters to our national security.

Between 1995 and 2009, the member states of the EU agreed unanimously about 135 measures relating to police and judicial cooperation in criminal justice matters. They included:

  • measures to combat drug trafficking
  • mutual legal assistance in criminal matters, including investigations and prosecutions
  • prisoner transfers, so that criminals can be sent home to serve their sentence
  • pooling of intelligence (reciprocal searching of EU databases for DNA profiles, fingerprints etc)
  • the European Arrest Warrant (see below)

The UK already has an ‘opt-out’ on these matters and indeed in 2013 notified the EU of its decision to exercise it, though it subsequently opted back in to around 35 measures (including those listed above).

If the UK were to leave the EU, the effect would be the same as opting out en bloc, though there would obviously be the potential to establish bilateral agreements in order to secure cooperation in particular areas. Once outside of the EU though, there would be no guarantee that other member states would be willing to agree to such cooperation on a case by case basis.

Bringing offenders to justice

Probably the most contentious area of EU cooperation on crime and justice relates to extradition. The European Arrest Warrant (EAW) scheme was incorporated into EU law in 2004, enabling individuals wanted in relation to specific crimes to be extradited between EU member states to face prosecution or serve a prison sentence for an existing conviction.

There is widespread consensus within UK law enforcement that the EAW is crucial to our national security – reducing both the delays and costs associated with extradition and aiding cross-border operations against organised crime, such as the recent joint UK-Czech and UK-Romanian action against people traffickers. High profile cases involving the EAW include the paedophile teacher Jeremy Forrest, who abducted  a pupil and fled to France, and fugitive bomber, Hussain Osman, who with accomplices had attempted to carry out a terror attack in London in July 2005 and had fled to Italy.

Concerns have been expressed about the proportionality of the EAW system, in particular, that it has been used for more minor crimes than the legislation was intended, leaving British citizens vulnerable to extradition to member states with less mature judicial systems than ours. A series of reviews (Scot Baker in 2011; House of Lords EU committee in 2013), have concluded that whilst the EAW does require reform, leaving it entirely would represent a risk to our national security.


On the basis of what we know about current levels of cooperation on border control, policing and extradition, it seems unlikely that pulling out of the EU would leave us any safer. Of course, leaving the EU would not preclude the UK from continuing to work with other EU countries to fight cross-border crime and terrorism, but unpicking the existing architecture for European security cooperation and rebuilding it from scratch would represent something of a leap into the unknown.

Jon Clements

Jon Clements

Director of Development

Jon Clements draws on nearly two decades experience in public affairs, the media and criminal justice to ensure Crest offers clients the support they need to achieve their goals. A former national newspaper and broadcast journalist, Jon leads on Crest’s positioning and oversees the development of new business and marketing.

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