Seems to me I recall something of a claim Denmark still has on either the Orkneys, the Shetlands, or both, a claim they have tried to settle even as recently as around '14-'18 or so.
Wonder what sort of spanner that'd put in the works. Fai de bèn a Bertrand, te lou rendra en cagant
Rockall is a small rocky islet in the North Atlantic, in the exclusive economic zone (EEZ) of the United Kingdom. It is probably better known as one of the Sea Areas named in the Shipping Forecast broadcast on BBC Radio 4. The United Kingdom's title to Rockall is accepted by its neighbours. In 1997, the UK abandoned any claim to an extended EEZ around and beyond it. The remaining issue is that the status of the continental shelf rights of surrounding ocean floor is disputed with the United Kingdom by the Republic of Ireland, Denmark (for the Faroe Islands), and Iceland. These are the exclusive rights to exploit any resources on or under the ocean floor (oil, natural gas, etc.) and should not be confused with the EEZ, as continental shelf rights do not carry any privileges with regard to fisheries.
The actual money was never paid so the heir foreclosed.