Following the unsuccessful European Defense Community initiative, the EEC and the European Atomic Energy Community were established in 1957 under the Treaty of Rome. In addition, the European Commission, the European Parliament, the Council, the Court of Justice and the Court of Auditors were formed to conduct the functioning of the community. In 1967, these three communities were merged with the Treaty of Fusion and became the European Community (EC) (Soyaltın, 2015: 13).
Although the Customs Union was completed in 1968, due to various economic problems in the international system, the common market phase could not be reached. Based on the White Paper of the Commission prepared in 1985, the Community has set itself the target of establishing a single market by January 1, 1993. In this context, the Single European Act came into force in 1987 (Ministry of Foreign Affairs, 2013).
In 1992, the Treaty of Maastricht, also known as the Treaty of the EU, was signed and entered into force in 1993 and the Community was renamed the European Union. Thus, the institutional structure was changed and a roof organization was established on three pillars. The first column is the European Communities, focusing on economic, social and environmental issues and giving supranational powers. The second column envisions the Common Foreign and Security Policy (CFSP) and the third pillar envisions intergovernmental cooperation on Justice and Home Affairs (Can, 2013: 43-44).
The EU organized a summit in Amsterdam in 1997 and the objectives of addressing the deficiencies of the Maastricht Treaty were defined as the Amsterdam Treaty. The establishment of the European Security and Defense Identity has been given importance, changes have been made regarding the institutional structure of the CFSP, the decision-making process and the types of savings, and a CFSP High Representative has been identified. It was decided to evaluate the Petersberg Missions (humanitarian aid and rescue, peacekeeping, intervention in crisis management and attempts to ensure peace) within the scope of CFSP (Özdal, 2008: 5). As a result of the agreement signed at the Nice summit held in 2000, changes were made in the size and composition of the Commission, in the Council of Ministers, the weight of votes, decision-making procedures and strengthened cooperation in the institutional structure (Akdemir, 2014: 54).
In 2004, the EU member states signed a Constitutional Treaty for Europe. However, this draft did not come into force after France and the Netherlands rejected the constitution draft for various reasons. In 2007, the Lisbon Treaty, which was a reform treaty to replace the constitution, was signed between the member states and entered into force in 2009. With the Treaty of Lisbon, a more democratic and transparent EU has been established. Freedom and principles contained in the Charter of Fundamental Rights which promote the values of the EU are guaranteed. Innovations have been made in the institutional structure. The powers assigned to the EU have been authorized to sign international treaties or to participate in an international organization in their field (European Parliament, 2018).
The EU has been founded on certain values and has taken its current form. It has the basic principles it expects from member states in order to ensure full integration. These principles defined in Lisbon Treaty: human dignity, freedom, peace, democracy, equality, the rule of law, respect for human rights and minority rights. These values are common to the Member States in a society in which pluralism, non-discrimination (EUR-Lex, 2007). In summary, as can be understood from the articles of the agreement, these principles briefly cover principles such as cohesion, equality, peace, freedom of movement, solidarity, respect for national identity, security, commitment to law, and transnationalism.