Reformed EU institutions to prepare for eastward enlargement by amending the Maastricht and Rome treaties.
Key Facts
- Signed
- 26 February 2001
- Entered into force
- 1 February 2003
- Irish referendum (first)
- Rejected, June 2001
- Irish referendum (second)
- Approved, approx. one year later
- Amended treaties
- Maastricht Treaty and Treaty of Rome
By the Numbers
Location
Cause → Event → Consequence
The Amsterdam Treaty had been expected to reform EU institutions in preparation for eastward expansion but failed to resolve the necessary structural changes, leaving the European Union inadequately equipped to absorb a larger number of member states.
European leaders signed the Treaty of Nice on 26 February 2001, amending both the Maastricht Treaty and the Treaty of Rome to restructure EU institutions and decision-making procedures in anticipation of significant enlargement eastward.
The treaty's ratification was delayed after Irish voters initially rejected it in a June 2001 referendum, but a second referendum reversed that result, allowing the treaty to enter into force on 1 February 2003 and paving the way for EU enlargement.
Political Outcome
Treaty ratified and entered into force on 1 February 2003, reforming EU institutional structure for eastward enlargement.
EU institutional framework under Amsterdam Treaty, unprepared for large-scale eastern enlargement
Reformed institutional structure capable of accommodating expanded EU membership