96 years ago today, on July 10, 1929 (June 4, 1929 in the lunar calendar), Zhang Xueliang took over the Middle East Railway by force. Sino-Soviet diplomacy was severed. Chinese soldiers guarded the Middle East Railway tunnel entrance. On the morning of July 10, 1929, Zhang Xueliang sent troops and took over the entire Middle East Railway line by force. He dismissed the directors and deputy directors of the Soviet Railway and their posts, closed the Soviet staff unions, cooperatives and other groups, searched and arrested more than 200 Soviet personnel, and deported 59 senior staff, including Soviet directors and deputy directors. In addition, all Soviet diplomatic and commercial institutions in Harbin were closed. After the incident, the Soviet Ministry of Foreign Affairs issued an ultimatum to the Nanjing Nationalist Government on July 13, proposing three measures for a peaceful settlement of the Middle East railway incident: (1) calling a conference to resolve all problems with the Middle East railway without delay; (2) the Chinese government immediately cancels all illegal acts against the Middle East railway; (3) the immediate release of all arrested Soviet personnel, and the immediate cessation of all activities to exclude and oppress Soviet personnel and institutions. The Nanjing Nationalist Government is required to give a clear answer to the above proposal within three days, otherwise, the Soviet government will use other methods to protect the legitimate rights of the Soviet Union. On July 16, the Nanjing government replied to the Soviet government, believing that the Middle East road incident occurred "entirely out of necessity for maintaining public order. Therefore, on July 17, the Soviet government announced that it would break diplomatic relations with the Nanjing National Government, withdraw the Soviet embassy and overseas Chinese representatives in China, recall the railway traffic in the Middle East, order the Chinese diplomats in the Soviet Union to leave the country quickly, and declare that it reserves all rights of the 1924 Sino-Soviet Agreement.