Japan presents one of the clearest examples of how Buddhism, despite its non-violent ideals, has become entangled with political and military life. From early connections with the imperial court to the active involvement of Buddhist institutions in feudal conflicts and modern wars, Japanese Buddhism reflects a long history of ethical contradictions and complex adaptations.
Buddhism entered Japan in 538 CE and quickly became linked with the state. By the Heian period (794–1185), a feudal society had emerged, and powerful monasteries operated not only as spiritual centers but also as landowners and political players. Some of these became militarized — giving rise to the sōhei, or warrior-monks. These monks engaged in armed conflict to defend their monasteries or to assert sectarian interests, especially during times of political instability when the central government was weak .
This sectarianism intensified in later centuries. Japanese Buddhists came to identify strongly with particular schools or sub-sects, which became fiercely competitive. Some temples amassed private armies and even launched raids on rival sects. In this environment, Buddhist values were often overshadowed by factionalism and violence .
The samurai class also integrated Buddhist teachings, particularly Zen, into their code of conduct — Bushidō. While Zen Buddhism promoted self-discipline, clarity of mind, and courage, Bushidō also included values directly opposed to Buddhist ethics, such as a duty to avenge wrongs and a disregard for life. Zen’s emphasis on focused action was sometimes distorted into a philosophy of martial detachment, culminating in the claim by some teachers that killing could be done mindfully — even as a form of spiritual expression .
This trend continued into the modern era. With the rise of State Shinto and nationalism during the Meiji period, Buddhism was at first suppressed as “foreign,” but later co-opted to support imperial ambitions. During the Russo-Japanese War (1904–1905) and World War II, some Buddhist leaders supported the war effort. Figures like Soyen Shaku attempted to harmonize Buddhism with nationalism, arguing that Japanese soldiers could fight and die “with ennobling thoughts of the Buddha.” Zen masters even trained soldiers to become “one” with their combat roles — a tragic misuse of Buddhist principles .
Not all Buddhists supported this trajectory. A few voices opposed militarism from the margins, and after the war, some Buddhist groups — particularly those inspired by Nichiren — turned to peace activism. The legacy of wartime complicity, however, remains a difficult chapter in Japanese Buddhist history.
Japanese Buddhism teaches us that spiritual ideals can be fragile when subjected to political forces. It also reminds us that ethical vigilance is needed not only in meditation halls but in the choices religious communities make in public life.