What country released the Sussex pledge?

The Sussex pledge was a promise made in 1916 during WWI by Germany to the US prior to the latter's entry into the war. Early in 1916, Germany instituted a policy of unrestricted submarine warfare, which allowed armed merchant ships and not passenger ships to be torpedoed without warning. Despite this avowed restriction, a French cross-channel passenger ferry, the Sussex was torpedoed without warning on March 24, 1916; severely damaged, and about 50 people died. Although no US citizens were killed in this attack, President Woodraw Wilson declared that if Germany continued this practice, the United States will break diplomatic relations with them. Fearing the entry of the United States into World War I, Germany tried to appease the United States by issuing, on May 4, 1916, the pledge, which promised a change in Germany's naval warfare policy. The promise held to these points:

Passenger ships will not be targeted; Merchant ships willnot be sunk until the presence of weapons was established, if necessary by a search of the ship; Merchant ships will not be sunk without provision for the safety of passengers and crew.

In 1917 Germany became convinced that they could defeat the Allied Forces by instituting unrestricted submarine warfare before the United States entered the war. The pledge was therefore rescinded in January 1917, thereby initiating the decisive stage of the so-called first battle of the atlantic. The resumption of unrestricted submarine warfare and the Zimmerman telegram caused the United States to declare war on Germany on April 6, 1917.