The Historical Development of European Integration and Treaties

Posted on Oct 7, 2025 in International Relations

Historical Context of 20th Century Europe

Europe was politically fragmented, despite historical attempts at unity via conquest (Charlemagne, Napoleon, Hitler). Enlightenment and liberal thinkers proposed peaceful integration:

  • William Penn (1693): Early vision of a European Parliament.
  • Saint-Simon (1814): Advocated for a European monarch and parliament to maintain peace.

World War I (1914–1918)

This global conflict pitted the Allies against the Central Powers. It was triggered by nationalism, imperial competition, and failed alliances, leading to massive destruction, the redrawing of borders, and the rise of new states.

  • Causes: German rise, Ottoman decline, industrial and economic rivalries.
  • Impact: Death toll reached 10 million military personnel and 10 million civilians. The Spanish flu pandemic was worsened by population movement during the war.

Post-WWI: Paris Peace Conference (1919–1920)

The Treaty of Versailles created resentment and imposed a punitive framework against Germany, which lost territories, was disarmed, and faced heavy reparations. Empires dissolved, leading to the creation of new states, including Poland, Finland, the Baltic states, Czechoslovakia, and Yugoslavia.

The Interwar Period (1918–1939)

The League of Nations (1920–1946)

The League of Nations was created but ultimately failed to maintain peace, reaching a maximum of 58 members. U.S. President Woodrow Wilson won the Nobel Peace Prize for its design and negotiation, but the U.S. never joined, harming the organization’s credibility.

Economic depression and the rise of fascism led to isolation and rearmament across Europe. National self-determination increased obstacles to cooperation, and instability arose from Germany’s defeat, economic crises, and tariff barriers.

World War II (1939–1945)

This global conflict involved the Allies versus the Axis powers (Germany, Italy, Japan), beginning with the German invasion of Poland on September 1, 1939. The war resulted in 70–85 million deaths (half of which were civilians), the Holocaust, and the nuclear bombings of Japan.

  • Germany surrendered: May 8, 1945.
  • Japan surrendered: August 15, 1945 (signed September 2).

Creation of the United Nations (1945)

Fifty nations met in San Francisco on April 25, 1945. The UN Charter was adopted on June 25 and became effective on October 25. The founders (U.S., U.K., France, China, U.S.S.R.) secured veto power in the Security Council.

Proposals for European Union During WWII

The war catalyzed ideas for European unity, promoting the abandonment of the independent state model in favor of a unified political community. Key resistance groups and proposals included:

  • The Ventotene Manifesto (1941) by Altiero Spinelli.
  • The Geneva Conference (1944).

Proposals included a federal Europe, a written constitution, a supranational government, a unified army, and a judicial tribunal. The U.S.S.R., U.S., and U.K. did not oppose unity. Britain even offered a Franco-British Union in 1940.

Post-war, old politicians prioritized reconstruction. Britain declined a leadership role (Churchill lost the elections), and Cold War tension suppressed unity ideas until 1989.

Post-War Reconstruction and the Push for Unity

Political and Strategic Drivers

The Cold War, fear of communism, and weakened European powers led to U.S. support for European unity.

  • Truman Doctrine (1947): U.S. aid to defend democracy (especially Greece and Turkey).
  • Marshall Plan (1948–1951): $13 billion in aid to rebuild Europe, conditioned on economic cooperation.

Functional Approach to Integration

Integration began with economic sectors to gradually build political union (functionalism). The OEEC and UNECE formed early cooperative frameworks.

Germany was divided into East and West. The UN was unable to resolve Cold War disputes. As Britain and France were weakened and Germany was prostrated, the U.S. filled the power vacuum.

Treaty of Paris (1951): European Coal and Steel Community

The ECSC was the first step toward European integration.

Timeline and Objectives of the ECSC

The ECSC was initiated by the Schuman Declaration (May 9, 1950). It was signed on April 18, 1951, and entered into force on July 23, 1952 (expiring exactly 50 years later, on July 23, 2002).

It created a common market and supranational institutions for coal and steel.

Key Articles of the ECSC Treaty

  • Art. 2–3: Promote employment, productivity, and economic expansion.
  • Art. 4: Prohibited tariffs, quotas, subsidies, and discrimination.
  • Art. 5–6: Limited intervention by the High Authority; financed via producer levies.

ECSC Institutions

  • High Authority: The executive body with 9 members; issued binding decisions.
  • Common Assembly: 78 members drawn from national parliaments.
  • Special Council of Ministers: The intergovernmental body.
  • Court of Justice: Oversaw legality; its rulings were final (no appeals).

Limitations and Legacy of the ECSC

The ECSC faced challenges from language barriers, institutional fragmentation, and state resistance. The 1959 coal crisis demonstrated the limits of the High Authority’s power. However, Court rulings established legal precedent and legitimacy, laying the groundwork for broader integration.

Treaty of Rome (1957): EEC and EURATOM

Signed on March 25, 1957, the treaties entered into force on January 1, 1958.

European Economic Community (EEC)

The EEC aimed to promote harmonious development, stability, and improved standards of living.

  • Art. 2: Defined the goal of promoting harmonious development, stability, and standards of living.
  • Art. 3: Established the common market, the four freedoms (goods, services, capital, people), and common policies.

EEC Institutional Design

Art. 4 established the core institutions:

  • Commission
  • Council
  • Assembly (later Parliament)
  • Court of Justice

The Economic and Social Committee served an advisory role.

EEC Sectoral Policies

  • Agriculture (Arts. 38–47)
  • Transport (Arts. 74–84)
  • Competition law: Prevented dumping and state aid (Arts. 85–94)
  • Social policy: Mandated equal pay (Art. 119)

EURATOM

Focused on the peaceful development of nuclear energy. Its institutions merged with the EEC in 1965 via the Merger Treaty. The Parliament held only a consultative role in EURATOM matters.

The Single European Act (1986)

Entered into force in 1987. It set the target to complete the internal market by 1992. It introduced the cooperation procedure and expanded the Parliament’s powers. It provided a legal basis for foreign policy coordination (European Political Cooperation) and extended qualified majority voting in the Council.

Maastricht Treaty (1992): Treaty on European Union

This treaty established the European Union and the three-pillar structure:

  1. European Communities (EC)
  2. Common Foreign and Security Policy (CFSP)
  3. Justice and Home Affairs (JHA)

It introduced EU citizenship, set the framework for Economic and Monetary Union (EMU), strengthened Parliament through the co-decision procedure, and extended areas of qualified majority voting.

Amsterdam Treaty (1997)

This treaty strengthened the role of the European Parliament, incorporated the Schengen acquis into EU law, and introduced the concept of “closer cooperation.”

Nice Treaty (2001)

The Nice Treaty reformed voting weights in the Council, prepared institutions for the eastern enlargement in 2004, and extended qualified majority voting in more policy areas.

Lisbon Treaty (2007)

The Lisbon Treaty (in force 2009) replaced the failed Constitutional Treaty. It abolished the three-pillar structure and gave the EU a single legal personality. Key changes included:

  • Creation of the President of the European Council and the High Representative for Foreign Affairs.
  • Making the Charter of Fundamental Rights legally binding.
  • Extended use of the Ordinary Legislative Procedure.
  • Strengthened the role of national parliaments in EU lawmaking.

Institutional Structure and Evolution

Council of Ministers

The Council uses weighted majority voting. The 1965 Empty Chair Crisis led to the 1966 Luxembourg Compromise, which effectively granted veto rights on vital national interests.

The European Commission

The Commission proposes legislation, acts in the EU interest, is independent, and executes EU law and the budget.

The European Parliament

The Parliament started as consultative but gradually gained budgetary and co-legislative powers. Direct elections began in 1979.

The Court of Justice (CJEU)

The Court ensures the uniform interpretation of EU law. Its preliminary rulings are binding on national courts. Today, it is part of the Court of Justice of the European Union (CJEU).

Evolution of EU Legislative Procedures

Consultation Procedure (1957)

The Commission drafts legislation, the Parliament gives an opinion, and the Council decides (the Council is not bound by the opinion).

Cooperation Procedure (1987)

Introduced by the Single European Act, this procedure gave the European Parliament a suspensory veto, increasing its influence. The Council needed unanimity to override EP objections in the second reading.

Ordinary Legislative Procedure (Post-1999)

Originally called Co-decision, this procedure (renamed by the Lisbon Treaty) makes the EP and the Council co-legislators. A Conciliation Committee resolves deadlocks. Parliament gained power as an effective veto and co-legislator.

Current Structure of the European Union

  • European Union (EU): Established by the Maastricht Treaty (1992), legally unified by Lisbon (2009).
  • European Parliament: Directly elected since 1979, co-legislates with the Council.
  • European Commission: Proposes laws, enforces treaties, and manages the EU budget.
  • Council of the EU: Co-legislates with Parliament, representing Member States.
  • Court of Justice of the European Union (CJEU): Ensures uniform interpretation of EU law.
  • Ordinary Legislative Procedure: The main law-making process since Lisbon.
  • Charter of Fundamental Rights: Legally binding since 2009.

Institutions and Treaties That No Longer Exist

  • ECSC (European Coal and Steel Community): Expired in 2002.
  • High Authority (ECSC executive): Replaced by the European Commission.
  • Common Assembly (ECSC): Evolved into the European Parliament.
  • EEC (European Economic Community): Became the EU in 1992.
  • Three-pillar structure (Maastricht): Abolished by the Lisbon Treaty.

Institutional Transformation

  • High Authority → became the European Commission.
  • Common Assembly → became the European Parliament.
  • ECSC/EEC/EURATOM institutions → merged under the Merger Treaty (1965).
  • EEC → became the European Union (via Maastricht).
  • Cooperation Procedure → replaced by Co-decision, then renamed Ordinary Legislative Procedure.
  • Court of Justice → became part of the Court of Justice of the EU (CJEU).