The "Cod War" (November 1975 - June 1976) occurred between Great Britain and Iceland. Iceland had declared that the ocean up to 200 miles 322 km) from its coast fell under Icelandic authority. Britain did not recognize the 200-mile exclusion zone, and as a result, there came to be an issue with British fishermen and their 'incursion' into the disputed zone. The 'war', which in fact was hardly a war at all with only a few shots being fired, saw British fishing trawlers have their nets cut by the Icelandic Coast Guard, and there were several incidents of ramming by Icelandic ships and British trawlers and frigates.

Iceland deployed a total of six Coast Guard vessels and two Polish-built stern trawlers which had been converted into Coast Guard vessels to enforce Icelandic control over fishing rights. In response, Great Britain deployed a total of twenty-two frigates, seven supply ships, nine tug-boats and three support ships to protect its fishing trawlers.

A more serious turn of events came when Iceland threatened closure of the NATO base at Keflavík, which would have severely impaired NATO's ability to defend the Atlantic Ocean from the Soviet Union. As a result, the British government agreed to have its fishermen stay outside Iceland's 200-mile exclusion zone without a specific agreement.

This was actually the third time Iceland and Great Britain had clashed over fishing rights. The first, in 1958, was the result of Britain's inability to prevent Iceland from extending its fishing limits from 4 miles to 12 miles off Iceland's coast. The second dispute occurred between 1972 and 1973. Iceland had extended its limits to 50 miles. An agreement between the two countries that bound British fishing to certain areas inside the 50 mile limit resolved the dispute that time. The resolution was on the premise that British trawlers would limit their annual catch to no more than 130,000 tons. This agreement expired in November, 1975, and the third "Cod War" began.