Minister of the United Kingdom. He failed when he discussed the revision of the unequal treaty with the U.S. president. The U.S. president pointed out that Iwakura did not have a commission of full powers. Ōkubo and Itō immediately returned to Japan on March 24 to get a commission of full powers and then returned to the United States on June 17. Despite their efforts, the United States was no longer interested in the revision of the unequal treaty at that time. In his observations, Iwakura was surprised at the economic prosperity in western countries. He was especially interested in the railways. Also, he learned the importance of religious problems in the United States and he thought that the prohibition of Christianity was an obstacle to change the unequal treaties. Besides, he felt the danger of rapid Westernization, because he saw and learned about the merits and demerits of Westernization. At first, this trip was planned for 10 months and a half, but it took a year and 10 months in the end. A celebration was held in Manchester and Liverpool in 1997 to celebrate the 125th anniversary of the Iwakura Mission. Before the return of the Iwakura mission, the dispatch of Saigō to Korea was decided in a cabinet meeting. Generally, people thought that the dispatch of Saigō was too dangerous, but Saigō persisted in his decision. On his return to Japan in 1873, he was just in time to prevent an invasion of Korea (Seikanron). Iwakura opposed the dispatch because he thought that Japan needed to see not only the Korean problem but also other foreign issues such as Karafuto and Taiwan. Also, Iwakura wanted to prevent the dispatch of Saigō to avoid foreign wars. Realizing that Japan was not in any position to challenge the western powers in its present state, he advocated strengthening the imperial institution, which he felt could be accomplished through a written constitution and a limited form of parliamentary democracy. Ōkubo supported Iwakura's idea. In the next meeting, Saigō was absent to imply his disposal in case his claim would not be accepted. Sanjō Sanetomi, a prime minister was surprised about it and suddenly changed his opinion from the opposition of dispatch to the acceptance of dispatch. A lot of members including Iwakura criticized the sudden mind change of Sanjō, and they requested their disposal. Sanjō panicked and he became unable to work