What is Unrestricted submarine warfare?
'''Unrestricted submarine warfare''' is a type of [[Navy|naval]] [[War|warfare]]. It was stared in February 1917 during the [[First World War]]. [[Germany]] began using a policy of [[submarine]] warfare in which they would sink all ships in war zone waters. This including both [[military]] and non-military ships. This policy affected [[United Kingdom|British]] supplies. {{military-stub}} [[Category:Submarines]] [[Category:World War I]]