Ever since its foundation, discussions have taken place about the role of the European Community on the world stage. The way that the EU operates means that it has many of the characteristics of a state. So, should it have an army and an ability to wage war? Some argue that the EU should speak with one voice on global issues. Since 1992, the EU has had official responsibility for a range of security and diplomatic questions. However, critics argue that the EU is not an effective player on the world stage because EU member states rarely all agree on the best approach to deal with foreign affairs.

Although the idea of a single European foreign and defence policy has existed since soon after World War II, during the Cold War it was the North Atlantic Treaty Organisation (NATO), a coalition of North American and European countries, that was primarily responsible for defending western Europe against a nuclear attack from the USSR. It was not until the Maastricht Treaty (1992) and the Amsterdam Treaty (1997) that the EU gained real power to make decisions about foreign and defence policy under the Common Foreign and Security Policy (CFSP).  This is now run by the EU High Representative for Foreign and Security Policy, currently Catherine Ashton. The position of High Representative was created by the Lisbon Treaty (2007) which aimed to strengthen the EU's voice on foreign and security policy. The Lisbon Treaty also created a new European External Action Service (EEAS) to represent all EU countries as a bloc in discussions with foreign governments under the leadership of the High Representative.

In the early 1990s, the EU had difficulty co-ordinating a foreign policy, as evidenced in its slow response to the genocides in the former Yugoslavia and Rwanda. However, in recent years, several EU peacekeeping missions have been deployed in Macedonia, DR Congo, Bosnia-Herzegovina and Chad.  The EU has also launched civilian operations to promote justice and the rule of law, train police forces and monitor elections in countries across the world including Georgia, Indonesia and Kosovo. In 2003, the EU established a European Defence Agency (EDA) to help co-ordinate the development of defence technology across the EU.

There are two driving forces behind developing a European foreign policy. First, there is a belief that through co-operation European nations can avoid a return to nationalistic conflicts.  The second belief is that European nations' voices will be heard more clearly if they are united. The emphasis of EU foreign policy is on diplomacy and multilateral action, which puts nation states within a larger framework of international co-operation. Although EU foreign policy does not require all member states to always agree, it does encourage consensus through common bodies such as the EDA and the recently established EEAS.

As the only global superpower, the USA plays an important part in EU foreign policy calculations. After World War II, the USA led the reconstruction of western Europe, however since the fall of the Berlin Wall in 1989, the USA and the EU have differed on many foreign policy issues. When the USA decided to invade Iraq in 2003, the EU was deeply divided over what its role should be. The USA also opposed the 2006 launch of the Galileo Satellite, which was built with Chinese involvement and which could serve a military use previously only provided by an American system.

A major aspect of the EU's foreign policy concerns it's relations with countries with which it shares either land or sea borders with. The EU relates with these nations through the European Neighbourhood Policy (ENP). This aims to persuade nations to embrace economic, political and social reforms in line with 'European values', through using incentives such as access to the single market, EU aid, and tariff reductions. This process may also involve a country signing an Association Agreement with the EU.

'[The European Union] must have the capacity for autonomous action, backed up by credible military forces, the means to decide to use them, and a readiness to do so, in response to international crises.' Tony Blair and Jacques Chirac, December 1998

'We do not interfere in American affairs. We hope they will have enough respect not to interfere in ours'.  Jacques Delors, EU Commission President, 1985-1995

'Germany has been a problem and France has been a problem, but you look at vast numbers of other countries in Europe, they're not with France and Germany... they're with the US.' Donald Rumsfeld, US Defence Secretary, 2003