One unavoidable fact about the modern world is that criminal gangs and terrorist groups work across national borders. A concern raised during the EU referendum campaign was that if the UK left the European Union, the UK would not be able to co-operate with other countries and their police forces in these vital areas. In the wake of recent terrorist attacks, it has been claimed by figures such as Dominic Grieve, the Tory chair of the Commons Intelligence and Security Committee in the last Parliament, that the UK must retain Europol membership after Brexit, even if this means “accepting EU rules and judicial oversight for the European Court of Justice (ECJ)”, while Sir Hugh Orde, former Chief Constable of the Police Service of Northern Ireland has stated that: “If we don’t have all this, it makes it a lot more difficult to do this crucial work. It is vital that we get to a situation as close to what we have as members of the EU as possible, though it is difficult to see how we do that.” However, co-operation will indeed continue after Brexit without the need for Europol membership. The UK has a long record of working internationally with other nations in the fields of justice and crime prevention via the relevant global and regional bodies. In addition, the UK works with other NATO members to detect and prevent terrorist activity. The UK is currently a member of/signatory to: The International Criminal Police Organisation (ICPO)/INTERPOL International Criminal Court (ICC or ICCt)/Rome Statute United Nations Office on Drugs and Crime (UNODC) World Customs Organisation (WCO) Organisation for Security and Co-operation in Europe (OSCE) The European Police Office/EUROPOL The UK is also a member of the Commission on Narcotic Drugs and the Commission on Crime Prevention and Criminal Justice (CCPCJ), both of which are subsidiary Bodies of the United Nations Economic and Social Council (ECOSOC). The UK is also affiliated with the NGO, the International Center for the Prevention of Crime (ICPC) and participates in the Council of Europe’s Committee of Experts on the Operation of European Conventions on Co-operation in Criminal Matters (PC-OC). Of these bodies, clearly the most important is Interpol. Originally established as the International Criminal Police Commission (ICPC) in 1923, it now has 190 member countries and branches in all corners of the globe. Interpol has huge databases containing millions of criminal records which member states can access 24 hours a day via a system called I-24/7. In addition to all the bodies already mentioned, the UK is also a member of the ‘Five Eyes’ Intelligence-sharing partnership. The bodies I have mentioned already are connected to each other via a bewilderingly complex web of agreements and partnerships. Interpol signed a Memorandum of Understanding with Europol in 2011 in order to “establish and maintain co-operation between the Parties in combating serious forms of organised international crime… In particular, this will be achieved through the exchange of operational, strategic, and technical information, the co-ordination of activities”. Europol has signed a Co-operation Agreement with the United Nations Office on Drugs and Crime (UNODC) in order “to facilitate co-operation between UNODC and Europol in combating serious forms of crime”. Similarly, Europol has also signed a Co-operation Agreement with the WCO. Likewise, Interpol has signed an ‘Arrangement on co-operation’ with the UNODC and has signed various agreements with the International Civil Aviation Organisation (ICAO), WCO, Organisation for Security and Co-operation in Europe (OSCE) and America’s Federal Bureau of Investigation (FBI). The Organisation for Security and Co-operation in Europe has 57 participating States including all current EU member states. OSCE dedicates much of its efforts into terrorism prevention. As the OSCE website states: “The OSCE promotes a co-operative and co-ordinated approach to countering terrorism at all levels, including co-ordination among national authorities, co-operation among states, co-operation with relevant international and regional organisations.” Amber Rudd, the Home Secretary, has previously said that: “Europol has played an important role in keeping us safe and we will be having discussions about how to continue some form of involvement within the agencies of the EU that help to keep us safe.” This does not necessarily mean, however, that the UK should seek to continue as a full member of Europol after Brexit. Several non-EU countries have signed agreements with Europol and so the UK could likely do the same. Examples include the USA, Switzerland, Norway and Canada. As the Europol website states: “In general, there are two types of co-operation agreement that Europol can enter into with states and other entities outside the EU: strategic and operational agreements… both types of agreement are aimed at enhancing cooperation between Europol and the country concerned”. At any rate, the importance of Europol is exaggerated. Formed in 1998, it is a relatively young organisation that relies heavily on UK involvement and expertise. According to media reports: “Britain is the largest contributor to Europol, sending 35,000 messages last year, and the UK leads the way in Europe in clamping down on cross-border child sexual exploitation and money laundering. Around 40 per cent of all Europol cases have some kind of UK involvement.” The EU’s member states are in fact obligated to work with the UK on transnational organised crime as they are signatories to the United Nations Convention Against Transnational Organised Crime (agreed in 2000). Interestingly, under Article 103 of the UN charter, in the event of a conflict between the obligations of the Members of the United Nations under the Charter (and by implication, UN Conventions and protocols) and their obligations under any other international agreement, their obligations under the UN take greater precedence. The UK is signed up to the world’s pre-eminent crime fighting organisations already. Given the very real threat of terrorism, the EU will seek a new reciprocal bilateral solution with the UK in order to ensure maximum co-operation. The UK should not seek full Europol membership or participation in the flawed European Arrest Warrant scheme. Instead it should sign a co-operation agreement with Europol and then either sign a bilateral extradition treaty with the EU or investigate whether we could fall back on the pre-existing European Convention on Extradition (ECE). After Brexit, co-operation with EU member states on crime and terrorism prevention should continue largely as it does at present – there just might be a small shift in focus and emphasis from co-operating via Europol to co-operating via Interpol and the OSCE.