WORLD HISTORY

Detailed explanation-1: -Germany’s resumption of submarine attacks on passenger and merchant ships in 1917 was the primary motivation behind Wilson’s decision to lead the United States into World War I.

Detailed explanation-2: -Wilson cited Germany’s violation of its pledge to suspend unrestricted submarine warfare in the North Atlantic and the Mediterranean, as well as its attempts to entice Mexico into an alliance against the United States, as his reasons for declaring war.

Detailed explanation-3: -On 4 February 1915, Germany declared a war zone around Britain, within which merchant ships were sunk without warning. This ‘unrestricted submarine warfare’ angered neutral countries, especially the United States.

Detailed explanation-4: -Answer and Explanation: The main result of Germany’s use of unrestricted submarine warfare during World War l was the entry of the United States into the conflict. Submarines had been attacking the ships of neutral countries, as well as, ships that carried civilian passengers.