JHA broadly encompasses two different sets of issues: migration and the fight against international organized crime. For the purposes of this paper, civil judicial cooperation and issues of fundamental rights are excluded. A brief history of JHA includes brief explanations of the following four factors that are driving European cooperation in JHA: a common approach to migration, a single market in crime, the prospect of bringing the countries of Central and Eastern Europe into the European Union, and public support in the member states for European Union-wide cooperation in JHA. The overview of JHA history also describes progress toward cooperation among European Union member states. The paper then outlines the main features of the European Union's policy on border controls, asylum, and immigration; and it highlights some of the inherent tensions and contradictions in this new field of European Union policy. This is followed by a profile of Europe's single market in crime. As criminal organizations have become more international and sophisticated in their criminal enterprises, the 15 member states of the European Union have more than 120 police forces, dozens of separate legal jurisdictions, and different judicial and policing traditions. The member states of the European Union realize that cooperation among member-state law enforcement agencies and the sharing of resources is necessary if transnational organized crime is to be countered. Various ways in which this cooperation is being realized are described in this paper. A separate section of the paper discusses Britain's dilemma in the efforts at cooperation, since Britain has reservations about conceding more power to the EU as an international body. Eight recommendations are offered for how the European Union member states can enhance JHA cooperation, with attention to Britain's reluctance to engage in international efforts that may erode its national sovereignty.