Seikanron

• Date: 1873
• Japanese: 征韓論 (seikanron)

The Seikanron, or "Debate on Invasion of Korea," was a prominent dispute between the genrô leaders of the early Meiji government, resulting in a significant split. While the final consensus was to not launch an invasion of Korea, Saigô Takamori was among those who quit the government as a result, later going on to organize a rebellion against the Meiji state.

The impetus to consider invading Korea at this time stemmed chiefly from two points. One, the Joseon royal court had claimed the Sô clan of Tsushima han as a vassal, and had engaged in diplomacy & trade with Japan on that basis for centuries. Now, with the abolition of the han, the Korean court not only saw its vassal being taken away from it, but further refused to continue or re-establish diplomatic & trade relations with the Meiji government, on a new basis. Thus, some members of the new government agitated for a punitive mission, to punish Korea for its insolence. Two, many expressed fears that Russia, the United Kingdom, or another of the Western powers might gain significant influence in Korea, or might even colonize the peninsula entirely, in the process denying Japan access to trade with Korea, and thus doing great harm to the Japanese economy; the establishment of any significant foreign military presence in or control over Korea would also present a significant military threat to Japan. Though the Meiji state did not in the end go to war over Korea in the 1870s, such fears remained active and powerful concerns through to the 1890s, when the Sino-Japanese War broke out over precisely these concerns. Saigô Takamori and Itagaki Taisuke were among the chief proponents of invading Korea in the 1870s; according to some sources, Saigô even considered having himself appointed ambassador and arranging for himself to be assassinated in Korea in order to provide justification for an invasion.

The chief opponents of the invasion included Kido Kôin, Ôkubo Toshimichi, and Saigô Tsugumichi. While some may have opposed the invasion entirely, Ôkubo expressed that Japan simply was not ready yet, and should not invade Korea yet at that time, citing chiefly issues of preparedness and the vast economic cost. Ôkubo also expressed fears that if the war in Korea should go badly at all, it would present far too great an opportunity for Russia or Britain to then come to "interfere in our internal affairs." He advocated strengthening the economy and the military, industrializing further, securing Japan's independence, and revising the Unequal Treaties before attempting any such invasion. Kido, meanwhile, along with Ôshima Tomonojô and certain other Tsushima officials, initially supported a punitive mission against Korea; however, by 1873, Kido had changed his mind, and now encouraged the government to focus on domestic affairs.

The government ultimately decided against an invasion of Korea, deciding around the same time to leave Sakhalin to the Russians, rather than inviting military conflict with Russia as well. Saigô Takamori, Etô Shinpei, Soejima Taneomi, and Itagaki Taisuke all resigned from the government as a result.