5.3 - European integration: treaties and monetary union

Treaty foundations and the common market

Early integration linked an economic project to the political aim of reducing the risk of European war.

The Treaty of Paris, signed in 1951 and effective in 1952, created the European Coal and Steel Community. Pooling these strategically important industries placed a defined area of national economic activity under shared institutions. The Treaties of Rome, signed in 1957 and effective in 1958, established the European Economic Community and Euratom. The EEC broadened cooperation towards a common market; Euratom concerned civil nuclear cooperation. These were distinct Communities, not the EU already operating under its later name. European Parliament account of the first treaties.

A customs union removes internal tariffs and applies a common external tariff to goods from outside. A common market goes further, seeking movement of goods, services, capital and people. The EEC customs union was completed in 1968. Removing tariffs did not remove every obstacle: incompatible product requirements or restrictions on services could still fragment markets. This explains pressure for subsequent integration. European Parliament account of early market development.

The Merger Treaty, signed in 1965 and effective in 1967, provided a single Commission and Council for the three Communities. The Assembly and Court were already shared. Administrative unification made cooperation more coherent without replacing national governments with one European state. Parliament's Merger Treaty account.

The single market and institutional reform

An ambitious market project needs institutions capable of agreeing and implementing common rules.

The Single European Act (SEA) was signed in 1986 and entered into force on 1 July 1987. It sought completion of the internal market and extended qualified majority voting in the Council. Majority voting reduced the opportunity for one government to block measures needed to remove market barriers. It also increased Parliament's involvement through the cooperation procedure and consent for accession. The economic aim therefore encouraged changes in political decision-making. EU treaty dates and purposes, Parliament's account of treaty developments.

Later treaties addressed both deeper cooperation and a growing membership:

These changes show the widening–deepening relationship. An enlarged membership can make the old rules harder to operate, encouraging reform. Governments may nevertheless resist losing influence or a veto. Institutional reform is consequently a negotiation over who decides, rather than an automatic administrative response to enlargement. Parliament on Amsterdam, EU record of Nice.

The Schengen Agreement of 1985 and Convention of 1990 developed the removal of internal border controls, alongside shared external-border and security arrangements. Amsterdam brought Schengen cooperation into the EU framework in 1999. Removing routine internal checks creates a need for cooperation over visas, policing and external borders: one member's decisions can affect others. Schengen rules allow temporary internal controls in specified circumstances, so border cooperation does not mean that checks can never return. Council explanation of Schengen, Amsterdam's incorporation of Schengen.

Maastricht and Lisbon: extending political integration

Integration beyond a common market has combined stronger shared authority with areas protected by national control.

The Maastricht Treaty, signed in 1992 and effective on 1 November 1993, established the European Union, introduced EU citizenship and set the route towards economic and monetary union. It also introduced co-decision, strengthening Parliament's law-making role. Its three-pillar structure combined the more supranational European Communities with intergovernmental cooperation in common foreign and security policy and justice and home affairs. A single treaty therefore extended cooperation without applying one decision method to every field. EU treaty overview, Parliament's Maastricht account.

The Lisbon Treaty, signed in 2007 and effective on 1 December 2009, extended Parliament's legislative powers, made the European Council a formal institution with a longer-term President, and strengthened arrangements for external representation through the High Representative. It replaced the earlier pillar structure, although foreign and security policy retained distinct rules with a strong governmental role. These changes aimed to make a larger Union act more consistently. EU account of Lisbon, Parliament on Lisbon's powers.

Lisbon followed an unsuccessful attempt at a Constitutional Treaty. The proposed constitution was signed in 2004 but did not come into force after rejection in French and Dutch referendums in 2005. This illustrates a political limit on integration: government agreement to a text does not ensure domestic approval. Lisbon enacted reforms through an amending treaty rather than making the unratified constitution operative. EU history of the constitutional proposal and Lisbon.

Treaty reform itself requires agreement and ratification by states. That supports an intergovernmental account of who authorises integration. Once powers exist, however, independent institutions and majority decisions can constrain individual governments. Distinguish the decision to create an institution from the institution's subsequent operation.