第一次世界大戰期間，德國為反制協約圓的攻勢，大量使用潛艇作為封鎖敵方海上交通的攻擊手段。由於潛艇受結構與通訊科技等因素的限制，潛艇攻擊非戰鬥船隻很難符合傳統海軍捕獲法有關先警告再攻擊的原則，因此引發許多爭議。本文的研究指出，潛艇作為一種新式武器，其作戰概念不同於傳統海面艦艇，在交戰的情況下，常違反既有戰爭法與慣例的標準。相對的，協約國（以英國為主）在對抗潛艇的作戰中所採取的偽裝、欺敵策略同樣未必符合戰爭法，形成更多問題。從這些爭議可以瞭解，戰時交戰雙方都以求勝為主要目標，對戰爭法僅做有利於己方的解釋，形成一種各說各話的情況，缺少共同標準。因此戰時德軍潛艇的行動雖被協約國廣泛宣傳為戰爭暴行，但在戰後僅有很少數的潛艇軍官因為違反戰爭法的緣故遭到處罰，形成輿論與現實間的巨大落差。

During World War I, the German Navy used submarines to attack Entente Powers’ sea traffic as a counter-blockade tactic. During that time, due to the technological and structural limitations, submarines struggled to apply the “law of prize” while attacking merchant ships. Because of this, the usage of submarines was very controversial. This study points out that the submarine was a new weapon, and its operational concepts differed from traditional navy warships. In wartime, it was difficult for submarines to follow the law of war. In contrast, the fact that Entente Powers’ (mainly England) antisubmarine warfare used camouflage and deception strategies also violated the laws of war, and caused more problems. These controversies show that both Entente and Central Powers targeted victory as main war purpose, and maintained the “law of war” only to their own benefit, leading to a lack of common standards. This helps explain why despite German submarine actions being widely propagandized as atrocities by Entente Powers, only a few submarine officers were punished after the war.