Through this paper, an argumentative answer will be given to the question of whether the motto of the European Union "united in diversity" is less and less present among the EU27 members, but also among the regions of the Republic of Croatia. Using statistical data from Eurostat and the State Statistical Office, the analysis leads to the conclusion that the Republic of Croatia has recorded economic growth and development since its entry into the European Union. With the further European integration that was achieved in 2023 by joining the Eurozone and Schengen at the same time and by using the increased funds from the EU funds in comparison to the previous period, Croatia has an exceptional opportunity to strengthen its social and economic determinants. Analyzing items such as GDP per inhabitant and the unemployment rate, we notice that the cohesion policy of the European Union differs in its effectiveness, that is, that it does not record the same results looking exclusively at countries and exclusively at regions. The social and legal values that the European Union fosters are of exceptional importance as a basis for economic growth and efforts to reduce differences. By investing in the education and training of a quality workforce, a country like Ireland has transformed itself from a less developed member of the European Union into one of the most developed, right next to Luxembourg, which breaks every average with its statistics. Also, the growth of populism and Euroscepticism in the current global peace crisis is shaking the foundations of the European Union as a bright spot of peace on the European continent and the desired integration of every European state.