The European Union (EU) and the North Atlantic Treaty Organisation (NATO) are two main treaty-based Western organisations for cooperation between member states, both headquartered in Brussels, Belgium. Their natures are different and they operate in different spheres: NATO is a purely intergovernmental organisation functioning as a military alliance whose primary task is to implement article 5 in the North Atlantic Treaty on collective territorial defence. The EU on the other hand is a partly supranational and partly intergovernmental sui generis entity akin to a confederation that entails wider economic and political integration. Unlike NATO, the EU pursues a foreign policy in its own right - based on consensus, and member states have equipped it with tools in the field of defence and cri