What is the Nice Treaty?
The Nice Treaty, which came into force in 2003, reformed the EU institutions in preparation for EU enlargement from 15 to 28 member states. The larger member states agreed to give up one of their two Commissioners (so there would now be one Commissioner per country) in return for larger voting weights for the big member states under qualified-majority voting in the EU Council. The Nice Treaty also extended the use of qualified-majority voting in the Council, including on the proposal of a Commission President to the European Parliament. The main policy change in the Nice Treaty was to bring defence policy co-operation into the treaty, establishing the EU as the ‘European pillar’ of NATO.