Lytton Report (リットン報告書 Ritton Hōkokusho ) was a report generated by a League of Nations commission in December 1931 to try to determine the causes of the Mukden Incident which led to the Empire of Japan’s seizure of Manchuria.
The Commission 
The Lytton Commission was headed by V. A. G. R. Bulwer-Lytton, the second Earl of Lytton of the United Kingdom, and included four other men, one each from the US (Major General Frank Ross McCoy), Germany (Dr. Heinrich Schnee), Italy (Count Aldrovandi-Marescotti), and France (General Henri Claudel). The group spent six weeks in Manchuria in spring 1932 on a fact-finding mission, after meeting with government leaders in the Republic of China and in Japan. It was hoped that the report generated by the Commission would help defuse the growing hostilities between Japan and China and would thus help maintain peace and stability in the Far East.
The Lytton Report 
The Lytton Report contained an account of the situation in Manchuria before September 1931, describing the unsatisfactory features of the Chinese administration and giving weight to the various claims and complaints of Japan. It then proceeded with a narrative of the events in Manchuria subsequent to September 18th 1931, based on the evidence of many participants and on that of eyewitnesses. It devoted particular attention to the origins and development of the State of Manchukuo, which had already been proclaimed by the time the Commission reached Manchuria. It also covered the question of the economic interests of Japan both in Manchuria and China as a whole, and the nature and effects of the Chinese anti-Japanese boycott. Russian interests in the region were also mentioned. Finally, the Commission submitted a study of the conditions to which, in its judgment, any satisfactory solution should conform, and made various proposals and suggestions as to how an agreement embodying these principles might be brought about.
However the report did not directly address one of its chief goals: the cause of the Mukden Incident. Instead it simply stated the Japanese position (that the Chinese had been responsible) - with no comment as to the truth or falsity of the Japanese claims. Although there was no doubt as to Japan's guilt among the five commission members, Claudel (the French delegate) insisted that Japan not be portrayed as the aggressor.
In spite of care to preserve impartiality between the conflicting views of China and Japan, the effect of the Report was regarded as a substantial vindication of the Chinese case on most fundamental issues. In particular, the Commission stated that the operations of the Imperial Japanese Army following on the Mukden incident could not be regarded as legitimate self-defense. Regarding Manchukuo, the Report concluded that the new State could not have been formed without the presence of Japanese troops; that it had no general Chinese support; and that it was not part of a genuine and spontaneous independent movement.
In September 1932, even before the official announcement of the findings of the Lytton Report on October 2 1932 were made public, the Japanese government extended official diplomatic recognition to the puppet government of Manchukuo. When the findings of the Report were announced before the General Assembly of the League of Nations, and a motion was raised to condemn Japan as an aggressor in February 1933, the Japanese delegation led by ambassador Yosuke Matsuoka walked out. Japan gave formal notice of its withdrawal from the League of Nations on March 27, 1933.
In the end, the Lytton Report basically served to show the weaknesses of the League of Nations and its inability with enforcing its decisions. The situation was complicated by the length of time it took for the Lytton Commission to prepare its report, during which time, Japan was able to firmly secure its control over Manchuria and was thus able to reject the condemnation of the League with impunity.
- Five Wise Westerners Time Magazine 10 Oct 1932
- The Mukden Incident by Thomas Ferrell, Journal of Modern History March 1955 (see page 67),
- Memo from the US Ambassador in Japan to the US Secretary of State, 16 July 1932, Foreign Relations of the United States, Japan 1931-1941 (see pages 93-94),
- Myopic Grandeur by John E. Dreifort (see pages 80-83)
- Walters, F. P. A History of The League of Nations. London, UK: Oxford University Press, 1960. pg 491-492