Relationship dossier
Ireland
United Kingdom
Relationship assessment
Durable cooperation on travel and Northern Ireland alongside recurring Brexit-related tensions
Ireland toward United Kingdom
+35The Irish government has worked with the UK government through the Belfast/Good Friday Agreement and its associated institutions to support peace and power-sharing in Northern Ireland. Ireland has also negotiated with the UK over post-Brexit arrangements affecting Northern Ireland and cross-border relations.
United Kingdom toward Ireland
+35The UK government entered the Belfast/Good Friday Agreement with Ireland and has cooperated through its institutions. It has also negotiated with the Irish government and the EU over post-Brexit arrangements for Northern Ireland, including the Windsor Framework.
Overall relationship
+30The relationship is structured by close practical cooperation, the Common Travel Area and joint commitments to the Northern Ireland peace settlement. Brexit has complicated that cooperation and prompted major disputes over Northern Ireland’s trade arrangements and constitutional sensitivities. These durable cooperative arrangements and recurring tensions support a mixed but generally cooperative assessment.
How to read these scores
Scores are rough judgments, not objective measurements or current verification. Directional scores describe government policy and conduct, not public opinion. The overall score is an independent estimate, never an average.
- −100
- Extreme sustained hostility
- −50
- Substantially adversarial
- 0
- Mixed or neutral, supported by knowledge
- +50
- Substantially cooperative
- +100
- Exceptionally close sustained partnership
“Not assessed” means there is no recorded score. Pair existence makes no claim about diplomatic recognition or established relations.
Relationship context
Overview
Ireland and the United Kingdom maintain substantial cooperation through the Common Travel Area and institutions created by the 1998 Belfast/Good Friday Agreement. Both governments have supported the Northern Ireland peace settlement, while Brexit arrangements and disputes over Northern Ireland’s constitutional and legacy issues have produced recurring strain. Cooperation is durable, but it coexists with significant disagreements.
Areas of tension
- Post-Brexit trade and regulatory arrangements for Northern Ireland
- The constitutional status of Northern Ireland and the conditions for any border poll
- Northern Ireland legacy investigations and accountability
Key developments
The Anglo-Irish Agreement established a framework for intergovernmental cooperation on Northern Ireland.
Ireland and the United Kingdom signed the Belfast/Good Friday Agreement, establishing a framework for peace and political institutions in Northern Ireland.
The UK and EU agreed the Windsor Framework to revise arrangements governing Northern Ireland after Brexit.
Major uncertainties
- The long-term effects of Brexit arrangements on cross-border cooperation remain uncertain.
- Implementation of agreements on Northern Ireland legacy issues remains contested.