Question

Why did Germany resume unrestricted submarine warfare in 1917?

Answer 1

Unrestricted submarine warfare was first introduced in World War I in early 1915, when Germany declared the area around the British Isles a war zone, in which all merchant ships, including those from neutral countries, would be attacked by the German navy.

Answer 2

Answer: it wanted to starve Britain and force them into making peace

Explanation: the blockade included no food. Germany told U.S. that if they could get Britain to take down their blockade against Germany, they would stop the unrestricted submarine warfare. Since the U.S. was unsuccessful, Germany proceeded with the submarine warfare.