As historian Ben-Yehuda states 1915 was the year in which the concept of unrestricted submarine warfare was first applied. Despite it not being a formal policy until two years later the shift towards this type of warfare was to have a profound effect on World War One and beyond. On the 18th February 1915 Germany announced the area surrounding the British Isles was now part of the war zone. This was the start of a commerce war against British exports but more importantly British imports. Germany wanted to strangle the British Isles of all its resources to win the war, much like the allies were conducting around the shores of Germany during this time. Germany had started ‘Handelskrieg’ meaning ‘trade warfare against Britain in an attempt to achieve victory. British reliance on American resources during this time were a key factor in motivating America to voice a warning to Germany. A formal announcement that the US would hold Germany responsible for any sinking of US ships was the first warning to Germany that their actions would have serious repercussions.
German U-boats were successful in their initial attacks, sinking merchant ships heading towards British ports which would have aided the war effort, it was the beginnings of what Germany hoped to be a key factor in achieving victory. Initial attacks worked on a code of ‘Prize rules’, a system in which the German U-boat would surface and allow the crew and passenger of merchant ships to get away before the ship would be sunk. However, this system did allow the U-boats to be attacked by allied naval forces, as such this vulnerability motivated Germany to abandon the ‘prize rules’ on which they initially operated by. In the period of March 1915 five thousand ships entered and left British ports however only 21 were attacked. However larger and more frequent attacks by Germany were soon to be implemented. Accompanying these attacks were more serious consequences which would change the course of World War One.
Sinking of Lusitania
The most famous sinking of any ship was that of the British ocean liner RMS Lusitania on the 7th May 1915. The Germans had made it no secret that they were employing unrestricted submarine warfare. Germany had advertised the dangers of travelling in the war zone in British and American publications. However, many considered it to be an idle threat so the Lusitania set sail from New York destined for Liverpool. Captain William Turner was confident of a successful voyage and his New York managers at Cunard publicised the safety of the ship. They released an official statement reassuring the public ‘The truth is that the Lusitania is the safest boat on the sea. She is too fast for any submarine. No German war vessel can get her or near her’. This was certainly not a misleading statement the Lusitania had the power and capabilities to get away from German U-boats and as such remain in relative safety. Yet complications with the weather forced slower speeds and little protection of the vessel led to such a tragedy. William Turners role in the sinking of the Lusitania is still hotly debated today as many see the loss of so many lives as avoidable and perhaps even a ploy by the British government to provoke the entrance of the US into the war.
The captain on the other side of this moment of history was Kapitanleutnant Walter Schweiger. A captain known for firing on ships without warning it was him who delivered the blows to sink the Lusitania. He was tasked with destroying ships arriving and departing from Liverpool, however before he could reach Liverpool his U-20s fuel was running low and as such he turned around before reaching Liverpool. This meant a direct confrontation with his German U-boat and the Lusitania, therefore such a tragedy was partly produced by the fate of low fuel. But it would be this moment which would have a profound impact on World War One and the concept of unrestricted submarine warfare.
18 Minutes Which Changed the World
Schweiger fired two shots from his U-20 boat and within 18 minutes the Lusitania was sunk. Of the 1959 individuals who were on board the ship 1,198 were killed during the incident with only 761 surviving. Of the incident 128 were American citizens who were killed by Schweiger’s U-boat. This incident was to have incredible repercussions for both Germany and the course of the war itself. Woodrow Wilson, the President of the United States, was prepared to enter the war due to the incident, however German negotiations delayed the entrance as they agreed to only shoot ships with contraband on. For now, Germany had avoided serious repercussions from their actions, but pressure was building from the allied forces and in particular the United Stares.
Germany attempted to justify the attack citing 173 tonnes of war munitions the ship had been carrying as an excuse for the attack. This was disputed by the British government and has long been covered up. However, with the release of British files it has been suggested that divers were warned of danger from war munitions when wanting to investigate the wreckage in 1982. It has been claimed this information was concealed to encourage American entry into the war and stop Germany being able to justify such an attack. Regardless of this, the incident had a profound effect on the world at the time. It was critical in turning public opinion against the Germans which would be an important factor in Americas eventual engagement in World War One. The Lusitania was by no means the sole reason of American entry into the war but it should be regarded as an important factor. More importantly it marked a shift in public opinion towards Germany and the war. It was also utilised as a tool by allied governments to bolster recruitment efforts. Similarly, riots broke out in many countries over the atrocity and in certain instances stores refused to serve Germans in response. The sinking therefore not surprisingly, drew a passionate and emotive response throughout the world. The impact of the sinking of the Lusitania therefore cannot be bound to the 18 minutes in which the tragic loss of life occurred but its impact extends far into World War One and even beyond.
The sinking of the Lusitania and other notable attacks including on the SS Arabic on the 19th August 1915 in which 44 passengers were killed including 3 Americans provoked responses from the US. Germany bowed to diplomatic pressure and the imminent threat of US entry into World War One. The German government in September 1915 had already begun restricting submarine use which meant German naval operations were entirely suspended for a brief period. However, with the lack of advance on the Western front and increasing hostility at Verdun Germany once again used unrestricted submarine warfare. The attack of the French passenger steamer Sussex on 24th March 1916 In which 50 people were killed and many more were injured including Americans increased pressure on Germany. As such political pressure and the threat of US entry into the war led on May 4th 1916 for Germany to limit its submarine warfare. Germany gave the ‘Sussex Pledge’ in which only merchant ships with contraband such as weaponry on-board would be sunk. Furthermore, any crew or passengers would have to be helped to leave the vessel before any torpedoes could be fired. Germany had to now find a balance between angering allied powers and risking provocation of the United States and the need to achieve victory in the war through unrestricted warfare.
A Return to Unrestricted Warfare
There was much resentment felt by officials in Germany over such passivity in the waters which surrounded Britain. In a conference on August 30th 1916 Admiral Von Holtzendorff, the naval chief of staff, claimed he wanted the policy of unrestricted submarine warfare to be implemented again as soon as possible. After the Battle of Jutland on the 31st May to the 1st June 1916 in which Germany were defeated by Britain, the pressure grew to resume the policy of unrestricted warfare. The Battle of Jutland involved Germans attempting to destroy British naval ships which had been enforcing the naval blockade of Germany. However, Britain wanted to contain Germany’s naval fleet and maintain freedom of trade in the area for Britain. Such a failure only pushed Germany towards starting unrestricted warfare once again.
On January 8th 1917 army and naval commanders could not proceed with such naval passivity in British waters. Therefore, ideas were presented to the Kaiser and German Chancellor Bethmann Hollweg to reinstate the policy of unrestricted warfare. There key argument was that which such a tactic employed they would be able to achieve a decisive victory in the war by the fall of 1917.. Both men were convinced and the tactic of unrestricted submarine warfare was officially implemented on February 1st 1917.
Between February and April 1917 German U-boats sank 500 merchant ships. Initial successes pointed to a correct decision to re-implement such a tactic. However, resuming attacks only heightened tensions further and edged the US closer into the World War. 10 German submarine attacks on US ships between February 3rd and April 4th 1917 only encouraged Wilson to bring the US into conflict, although not the primary reason for US entry into World War One the effects of such attacks should not be discounted. Notable sinking’s in this including the passenger ship Housatonic on February 3rd 1917 and the Marguerite on April 4th 1917.
The End For Germany
It is no doubt such a campaign of unrestricted warfare by Germany was a factor in American involvement in the European theatre of war. It was perhaps not the major one but was extremely vital in changing public perceptions and edging the US closer to combat. With American entry into World War One occurring on April 6th 1917 the tide immediately shifted for the course of the war and German defeat was looming. A continuation of the policy of unrestricted submarine warfare occurred however it was clear the outcome of the war regardless of such naval activity. By mid-October 1918 many officials and troops were resenting and becoming frustrated with such activity. Culminating in this frustration was Admiral Reinhardt Scheer issued an order to all navy submarines to return to German bases. The policy of unrestricted submarine warfare had now come to an end for Germany in World War One. The final ship sunk was on October 21st 1918, the British merchant ship the Saint Barcham in the Irish Sea. By the end of World War One 344 U-boats of which 178 had been sunk had been used by Germany resulting in the loss of 15,000 lives and the sinking of 5,000 ships. The Germans had started an era of submarine warfare which would be used far beyond the scope of World War One into battles such as World War Two. Therefore, the use of submarine warfare by the Germans marked a significant shift in how modern warfare would be conducted.
If you would like to find out more here is a link to an interactive map of German U-boat activity in the war period: Interactive map of U-boat activity