WWI was not just a war fought using pure military prowess, but it was also an economic battle. In fact, crippling the economy of another country would severely hamper their war efforts as they would be unable to purchase and effectively allocate resources to fund their war efforts.
In November 1914 Britain’s First Lord of the Admiralty, Winston Churchill, declared that it was his country’s intention to strangle Germany’s economy by means of a naval blockade.
Two weeks later, Admiral Tirpitz announced that Germany would do the same by sinking British merchant ships.
Both the British and German’s actions were primarily designed to cause suffering to civilians. This affected merchant, warships, neutral countries and combatants.
Total War in WWI 