The Futility of Japanese Submarine Warfare in WWII: Understanding Their Strategic Flaws

In World War II, the Japanese submarine arm faced significant challenges that rendered their efforts largely ineffective. Unlike the German U-boats, which focused primarily on disrupting supply lines through merchant ship attacks, the Japanese submarines often targeted enemy warships. This strategic choice ultimately weakened Japan's war effort and contributed to its eventual defeat. This analysis delves into the reasons behind this approach and its impact on the outcome of the war.

Strategic Focus on Enemy Warships

The Japanese submarine doctrine was rooted in the idea of focusing on enemy combatant vessels, specifically warships. The belief was that engaging in direct combat with enemy ships could lead to decisive victories that would turn the tide of the war. However, this approach had several drawbacks.

Firstly, attacking warships often led to counterattacks from the enemy. Given the significant risks involved in such engagements, the submarines faced a higher likelihood of being destroyed. In addition, the enemy counterattacks could severely damage Japanese submarines.

Secondary Target: Merchant Ships

Secondly, economic warfare, which targets merchant ships, is a highly effective strategy for disrupting an enemy's war effort. While German U-boats and Allied subs efficiently targeted merchant ships, Japanese submarines largely ignored them. The Japanese policy of prioritizing warship targets rendered their efforts less impactful in terms of overall war effort.

Resource Limitations and Technological Challenges

The Japanese submarine arm was burdened by significant resource limitations. For instance, the allies in the Atlantic could repeatedly depth charge submarines almost endlessly, a luxury that Japan could not afford with its limited supply of depth charges. Moreover, the Japanese sonar technology was not highly advanced. A destroyer could not even use sonar effectively at speeds exceeding 18 knots, a limitation that hindered their ability to detect and track enemy submarines.

Inadequate Doctrine and Strategy

Furthermore, the Japanese did not have a robust doctrine for handling the new technologies and strategies employed by the Allies. They were fixated on the idea of a single, decisive battle, where submarines were to scout and attrit the enemy battle fleet. However, this strategy was no longer effective due to the overwhelming Allied superiorities in technology and tactics.

Consequences and Legacy

By the end of the war, Japanese naval command had come to understand that their lack of focus on disrupting Allied supply lines, combined with their failure to effectively use their submarines, had been a critical factor in their defeat. The merchant losses and the inability to support their forces through effective submarine operations played a substantial role in Japan's inability to sustain the war.

Conclusion

The Japanese submarine arm in WWII was a strategic misstep that contributed to Japan's eventual defeat. While their submarines were technologically capable, their focus on warship engagements rather than economic warfare was misguided. This underscores the importance of strategic adaptation and tactical flexibility in achieving naval objectives during wartime. For those interested in further exploring this topic, a detailed analysis of Japanese Subchasers can provide additional insights.