UDC 327(410:417)\"2020/...\"
Biblid: 0543-3657, 77 (2026)
Vol. 77, No 1198, pp. 603-645
DOI: https://doi.org/10.18485/iipe_ria.2026.77.1198.3

Review article
Received: 30 Mar 2026
Accepted: 31 Jul 2026
CC BY-SA 4.0

RELATIONSHIPS BETWEEN THE REPUBLIC OF IRELAND AND THE UNITED KINGDOM BEYOND 2020

DUJIĆ Ivan (Senior Research Fellow, Institute of International Politics and Economics, Belgrade, Serbia), ivan@diplomacy.bg.ac.rs

This paper addresses an important issue in the inter-state behaviour of the Republic of Ireland and the United Kingdom (UK), including their differing foreign policies. It analyses the impact of Brexit on the relationships of these two neighbouring countries – the Republic of Ireland, a member of the European Union (EU), and the UK, a non-EU member since 2020. Using comparative, historical, and statistical methods, this paper aims to answer the research question: Can the Republic of Ireland and the UK maintain their relationship in the spirit of peaceful coexistence? This question is not only thought-provoking but also essential for the future of both nations, particularly in the post-Brexit era. The paper presents findings on the cooperation between the Republic of Ireland and the UK, aiming to mitigate their inter-state conflicts and support the UK’s intra-state unity in the coming years. The conclusion reveals that the UK’s “reason of state”, rooted in its intra-state unity and cooperation with the Republic of Ireland, carries significant implications for the future of both countries, influencing their direction in the post-Brexit landscape.

Keywords: Republic of Ireland; United Kingdom; European Union; cooperation; reason of state.