Fisheries Jurisdiction (United Kingdom v. Iceland)

The United Kingdom (plaintiff) and Iceland (defendant) had an earlier treaty in which the UK agreed to recognize Iceland's 12-mile exclusive fisheries jurisdiction in exchange for Iceland's agreement to submit any future fisheries jurisdiction disputes to the ICJ. When Iceland later sought to extend its exclusive fisheries jurisdiction from 12 to 50 miles, the UK challenged the extension and sought to bring the dispute before the ICJ under that treaty. Iceland argued it was no longer bound to submit to ICJ jurisdiction, contending that international law had since evolved so that a 12-mile limit was now the standard default for all states -- meaning its earlier agreement to a 12-mile limit, which had once been a genuine compromise, was now essentially meaningless, voiding the treaty for lack of consideration on the UK's part.