Saigō Takamori and his supporters insisted that Japan confront Korea due to the latter's refusal to recognize the legitimacy of the Emperor Meiji as head of state of the Empire of Japan, and insulting treatment meted out to Japanese envoys attempting to establish trade and diplomatic relations. The war-party also saw the issue in Korea to be an ideal opportunity to find meaningful employment for the thousands of out-of-work samurai, who had lost most of their income and social standing in the new Meiji social and economic order. These samurai posed a threat to the government, and (as a samurai himself) Saigō sympathized with their situation.
According to orthodoxy, "Saigo himself volunteered to go to Korea as a special envoy, inviting an assassination attempt that would provide justification, if any were needed, for a punitive expedition." However Saigo's statement was an attempt to win over the support of Itagaki Taisuke. Additionally, while the expedition to Korea was aimed at providing income for unemployed samurai, Saigo did not object to the Inoue-Yoshida plan, which abolished samurai stipends. Thus Saigo's condemnation of Meiji's provocation against Korea in 1876 suggests that Saigo had always been to "establish a firm relationship." In any case the other Japanese leaders strongly opposed these plans, partly from budgetary considerations, and partly from realization of the weakness of Japan compared with the Western countries from what they had witnessed during the Iwakura Mission.
While orthodox historians view the dispute as a matter of whether or not to invade Korea, the provocation against Korea in 1876 supports the claim that the Iwakura party never disagreed on the validity on an attack. Revisionists see the Seikanron as not a dispute of whether to invade, but instead when and who to do it. The former because those returning from the Iwakura Mission believed that Japan was too weak to attract international attention and needed to focus on internal reforms, the latter because the separation of the government between the caretaker government and the Iwakura groups allowed power-struggle between them. (Okubo, for example, had no real position of power at that time, seeing as his position was taken up after his departure). The arguments against invading Korea were outlined in Okubo Toshimichi's "7 Points Document", dated October 1873, in which he argued that action against Korea was premature because Japan was in the stages of modernizing and an invasion would be far too costly for Japan to sustain. Okubo's views were supported by the anti-war faction which mostly consisted of those returning from the Iwakura Mission. Iwakura had the emperor reverse the decision to send Saigo as an envoy to Korea, thus putting an end to the debate.
As it was decided that no action was to be taken against Korea, many of the War Party, including Saigō and Itagaki, resigned from their government positions in protest. Saigō returned to his hometown of Kagoshima, although he was never officially resigned from his role in the palace guard. Some historians (mainly orthodox) suggests that this political split paved the way for the 1874 Saga rebellion and the 1877 Satsuma Rebellion. Itagaki, on the other hand, became involved with the Aikoku Kōtō, a liberal political party, and rebelled against the Iwakura clique through legal means.
- Norman, E. Herbert; Woods, Lawrence Timothy (2000). Japan's emergence as a modern state: political and economic problems of the Meiji period. UBC Press. p. 85. ISBN 0-7748-0822-5. "Inflamed by such incidents, and coming out in support of the Seikan Ron (advocacy of a punitive expedition to Korea) various cliques agitated immediate invasion of Korea."
- Hunter, P.43.
- Yates, P 145.
- Kyu Hyun Kim, The Age of Visions and Arguments: Parliamentarianism and the National Public Sphere in Early Meiji Japan, p. 81
- Inoue: Saigo Takamori zenshu III: 414-16.
- Charles L. Yates, Saigo Takamori: The Man Behind the Myth. Kegan Paul International Limited (1995). ISBN 0-7103-0484
- Duus, Peter (1998). The Abacus and the Sword: The Japanese Penetration of Korea. University of California Press. ISBN 0-52092-090-2.
- Inoue Kiyoshi, Saigo Takamori zenshu (Japanese)
- Janet E. Hunter, The Emergence of Modern Japan (1989) ISBN 0-582-49407-9