- International disputes: Northern Ireland issue with the UK (historic peace agreement signed 10 April 1998); Rockall continental shelf dispute involving Denmark, Iceland, and the UK (Ireland and the UK have signed a boundary agreement in the Rockall area)
- Illegal recreational drugs: The Republic is transshipment point for and consumer of hashish from North Africa to the UK and Netherlands and of European-produced synthetic drugs; minor transshipment point for heroin and cocaine destined for Western Europe.
See also: Republic of Ireland, Foreign relations of the United Kingdom.