The significance of the establishment of the European Union lies in its aim to promote economic and political integration among European nations. Formed in the aftermath of World War II, the EU sought to foster peace, stability, and prosperity in Europe by creating a single market, allowing free movement of goods, services, people, and capital. The EU has also played a crucial role in promoting cooperation across member states on various issues including security, climate change, and human rights, making it a significant actor in global affairs.