How has the European Union affected the sovereignty of its member states?

The European Union (EU) has significantly altered the traditional concept of absolute national sovereignty by establishing a supranational legal and political framework that member states participate in to foster peace and economic prosperity. This process, often described as "divided sovereignty," involves states pooling their authority to address issues that transcend national borders.1

Key ways the EU affects member state sovereignty include:

• Legal Supremacy: EU law is supreme over national laws, meaning it has a direct effect on domestic legal systems. This authority reaches into areas such as contracts, business, labor, immigration, and consumer law.23
• Institutional Authority: Through treaties like the Maastricht Treaty, the EU gained broader control over policies including public health, environmental protection, and education. Member states also relinquished control over their national currencies and exchange rates upon adopting the euro.4
• Legislative Processes: The EU has expanded the use of qualified majority voting in the Council of Ministers, limiting the ability of individual states to veto legislation.4
• Enforcement: The European Court of Justice interprets and enforces EU law and has the authority to impose fines on member states for noncompliance.24

While these integrations limit domestic policy choices, they reflect a recognition that effective governance in an interdependent world often requires moving beyond the constraints of traditional, absolute sovereignty.51