Norway bans submarines from its waters

On 13 October 1916 the government of Norway issued a royal decree forbidding the submarines of belligerent powers to enter Norwegian territorial waters. An exception was made only for vessels seeking shelter from a storm or saving human life. They then had to proceed on the surface and flying their flag. A commander who broke the ban exposed his boat to attack without warning. Submarines of neutral states could still enter Norwegian waters, but they were warned that they ran a risk unless they approached the coast on the surface and in good visibility. The decree came into force on 20 October.

Formally the ban applied to all belligerents, but everyone understood against whom it was aimed. Norway had one of the largest merchant fleets in the world, and its ships largely sailed for the Entente. By August 1916, by Norwegian reckoning, the country had lost 135 ships and 144 seamen. In the summer the government in Kristiania (Oslo) concluded secret agreements with Britain under which the British bought up Norwegian fish, and exports of copper and pyrites to Germany were halted. The Germans responded with intensified attacks on Norwegian ships: on the route to Archangel, off the coast of Finnmark and on the coal route from Wales to France. According to the British official history, in September Norway lost 26 ships, and another seven in Arctic waters. Survivors reached ports such as Vardø exhausted after many days in lifeboats.

At the beginning of October the Norwegian press demanded redress and retaliation from the government of Prime Minister Gunnar Knudsen and Foreign Minister Nils Claus Ihlen. It was claimed that German submarines were hiding in remote bays and taking on supplies on the Norwegian shore. According to the British official history of the blockade, Norwegian naval commanders knew this was not so and that the German boats sailed straight to their operational areas. They also knew that their small fleet, made up of a few coastal defence ships and torpedo boats, could not watch over the most indented coastline in Europe. The ban itself was therefore of little military importance. Of greater weight was the fact that, according to the same source, the government decided in secret that if Germany gave no satisfaction, it would halt all exports to Germany. The Germans bought zinc, nickel and saltpetre in Norway, which they badly needed.

Berlin reacted sharply. Around 22 October the German minister lodged a protest, and at the end of the month the Norwegians feared an ultimatum and even a declaration of war. The British War Committee decided that Norway must be encouraged to resist and promised it Allied help if war came. In Kristiania, however, a middle course was chosen. With Swedish support, the tension was defused by negotiation. On 2 December the government, in a secret instruction to the navy, adopted an interpretation of the exceptions to the ban that was favourable to Germany, and on 23 January 1917 it concluded a provisional trade agreement with Germany in which Norway promised not to ban exports to Germany of, among other things, nickel, molybdenum and canned fish. This did not stop the sinking of Norwegian ships. According to the British official history of the blockade, the Germans sank 29 of them in November, 39 in December and 41 in January 1917. A royal resolution of 30 January 1917, in force from 6 February, publicly relaxed the decree. The ban still applied to the submarines of belligerent powers, while those of neutral states could enter Norwegian waters on the previous terms. The dispute over whether the ban was being observed lasted until the end of the war. In 1918 the British, with evidence that German submarines were slipping through Norwegian waters, pressed the Norwegians to enforce their own decree and to mine the passages along the coast.