Theobald Theodor Friedrich Alfred von Bethmann Hollweg was a German politician who was Chancellor of the German Empire from 1909 to 1917. He oversaw the German entry into World War I and played a key role during its first three years. He was replaced as chancellor in July 1917 due in large part to opposition to his moderate policies by leaders in the military.

Unrestricted submarine warfare is a type of naval warfare in which submarines sink merchant ships such as freighters and tankers without warning. The use of unrestricted submarine warfare has had significant impacts on international relations in regards to both the First World War and the Second World War. Its history has been dominated by German decision making.