The United Kingdom and the European Union: Joining, membership and leaving EU by international and EU law and the lessons that can be drawn from for Turkey

The origins of the idea of a united Europe date back to philosophers and statesmen who have long advocated for its discourse and development. However, the transformation of integration into a political project, within the national interests and capabilities of European states, came about as a result of the recognition that repeated wars and the ensuing financial disputes could not be resolved. Indeed, Europe has been the stage for frequent bloody wars for centuries. The belief that the only way to prevent wars was through the economic and political integration of nations gained momentum amongst European statesmen after the Second World War, leading to efforts to establish lasting peace in Europe. The common European ideal, which initially emerged in the Middle Ages primarily as a concept of military defense, evolved into an aspiration for economic unity as a result of increased production during the Industrial Revolution and the pursuit of open markets by states. This study will first examine the historical developments surrounding the idea of a united Europe, followed by an analysis of the United Kingdom's process of joining the European Union. Subsequently, the study will address the problem areas encountered after membership and discuss the developments related to the separation process known as "Brexit," concluding with the implications of the departure and the lessons that can be drawn for Turkey. This study, particularly in its final section, aims to provide enlightening insights for politicians, academics, and stakeholders who support the EU-Turkey relationship, and it will serve as a guide to Turkey's future in the European sphere.