Europe is a continent that is unique in its content in terms its varied backgrounds of cultures, ethniciteis, nationalities and languages. Subsequently, in order to establish a new entity there must be many difficulties ahead of unification of all European countries.
The term Europeanization was at, the beginning, driven by economical factors by establishing ECSC (European Coal and Steel Community) founded by the treaty of Paris after The Second World War and member states were France, Germany, Italy and Benelux -economic customs union which was founded in 1948 of Belgium Luxembourg and the Netherlands-. The need for such community was an essential step and principle to move to other agreements.
These countries had agreed to work on this field in 1951 because they wanted to have a strong economy by working together to rebuild it after they had lost a great amount of their economies during wars among each other. When the USSR collapsed in 1989, there were more tendencies and desires to enlarge their union by solving their problems such as the unification of West and East Germany in 1990, as well as allowing other states entering the union gradually after they met the standards and qualifications of all requirements.
The most important treaty is called Maastricht Treaty, which played a crucial role in currency union-euro- comprises of about seventeen states only which they think it can strengthen the economy. However, they haven't reached a concrete political agreement because they consider that national sovereignty is more valuable than to give up some of their autonomy.
After all, it is clear that the European countries have some barriers which impede them to become federal united of Europe in defense, currency, and one economy, as well as some other concerning issues, because some big European states do not want to give up their national sovereignty for the sake of unification.
