In times of war the Royal Norwegian Navy would have been reinforced by the Sea Home Guard, which manned older vessels taken out of service by the navy: Additionally the Royal Norwegian Navy would have been reinforced in wartime with three offshore patrol vessels of the Coast Guard: In 1981 the governments of Norway and the United States signed a Memorandum of Understanding that in case of war the U.S. Marine Corps' 4th Marine Expeditionary Brigade would be deployed to Norway as the Norway Air-Landed Marine Expeditionary Brigade (NALMEB).

[citation needed] To facilitate a rapid deployment of the brigade and its associated air and logistical units via strategic airlift the two nations agreed to preposition equipment and materiel for 15,000 troops, and war stocks for 30 days in Norway.

Thus between 1985 and 1989 American and Norwegian engineers drilled nearly 63,000 square meters of underground storage tunnels into the mountains around Trondheim.

After the sites had been filled with materiel and equipment, Norwegian troops were tasked with its maintenance, with two exceptions: the two stored fleet hospitals were maintained by two small US Navy detachments.

[4] The eight underground depots were:[citation needed] Additionally the U.S. military maintained a small number of units in Southern Norway in peacetime: