“The sinking of the giant English steamship is a success…,” (German newspaper from May 1915, Source C p38).
The sinking outraged the British and even the Americans started furiously protesting to the Germans. For them it was a big disaster among many, that eventually made them join the war (2 years later). That is one way that in the long term, the German unrestricted submarine warfare failed; it partly brought the Americans into WW1. The allies used this disaster as an excuse to bring out more propaganda. And thus another, minor, short term failure for the Germans; more people enlisted, outraged at what had happened. It made the country more determined as a whole.
In direct terms the first campaign didn’t go too badly for the Germans. German U-Boats sank almost 750,000 tons of British shipping. Sounds a lot but was only 4% of British shipping at the time. But what really upset the Germans in this first campaign was all the innocents killed, such as on the Lusitania, and their deaths exploited in a “propaganda bonanza”. A relatively small number were, but to a country’s population, every person counts. The outrage and the propaganda that came out from the allies made a huge amount of people furious at the Germans, including the Americans. The Germans did call an end to unrestricted submarine warfare soon after the sinking of the Lusitania.
In February 1917, the second campaign of unrestricted submarine warfare by the Germans began. This time, however, the campaign was better prepared, with the Germans using 300 submarines. Their motives were the same as before; to starve Britain and bring it to the peace table. They were well aware that the Americans were likely to enter the war, because they were attacking American ships. But they thought and hoped that Britain would come to terms with Germany, or be defeated before the Americans could help.
This campaign seemed to be going quite well for the Germans. In April 1917, people in high places in the Royal Navy were claiming that there was little food left in Britain. This and the release of posters such as “Save the Wheat and Help the Fleet…Eat Less Bread” were really some of the first admissions of partial German success. And the facts verify this; 379 British ships were sunk between January and the end of April by German U-boats. However just as things seemed to be going quite well for the Germans, two things happened that put an end to their unrestricted submarine warfare of 1917. The first was expected; the USA joined the war. It had little initial effect on the war, because just as the Germans predicted, it took the Americans a few months before trained troops could arrive at France. But the second was unexpected; the Royal Navy introduced a convoy system. This meant that merchant ships travelled in groups protected by warships, and sailed in a zigzag pattern. Thus far fewer British ships were sunk. This put an end to the German unrestricted submarine warfare.
The 1915 campaign for the Germans was initially a failure. But it was bound to be unless the Germans inflicted very serious damage on Britain. Otherwise every incident would be exploited like it was. But the Germans learnt their lesson and gained experience from the campaign. Experience that they used in their second campaign very successfully. I believe that Britain was quite close to exceptionally large losses, and to defeat in 1917. The Germans risked war with the USA because they had to defeat the British. Cutting off British supply lines meant less supplies to Britain, less to its troops. It would give Germany and its allies the advantage they would need to inflict major losses on their enemy. So it was not completely the fault of the German government that the U-boat campaign of 1917 was a failure. They expected the USA to join the war, and they did. But they were wrong not to expect the introduction of the convoy system, something that should have been introduced earlier.
