The Lansing-Ishii Agreement of 1917

Japan's Special Envoy Ishii with U.S. Secretary of State Lansing

The Lansing-Ishii Agreement, 1917, was a diplomatic note signed between the United States and the Empire of Japan on 2 November 1917 over their disputes with regard to China. It was intended to lessen the tension in the feuds between the U.S. and Japan over China. 

In the published text of the agreement, signed by United States secretary of state Robert Lansing and Japanese special envoy Ishii Kikujirō, both parties pledged to uphold the Open Door Policy in China, with respect to its territorial and administrative integrity. However, the United States government also acknowledged that Japan had "special interests" in China due to its geographic proximity, especially in those areas of China adjacent to Japanese territory, which was in effect, a contradiction to the Open Door Policy.

In a secret protocol attached to the public Agreement, both parties agreed not to take advantage of the special opportunities presented by World War I to seek special rights or privileges in China at the expense of other nations allied in the war effort against Germany.

At the time, the Lansing–Ishii Agreement was touted as evidence that Japan and the United States had laid to rest their increasingly acrimonious rivalry over China, and the Agreement was hailed as a landmark in Japan-United States relations. However, critics soon realized that the vagueness and differing possible interpretations of the agreement meant that nothing had really been decided after two months of talks. The Lansing–Ishii Agreement was abrogated in April 1923 in response to Japanese policy in China.

Source: Revolvy Website