20, 1924. The Secret Protocol stated that all former conventions, treaties, protocols, contracts, and documents between the Soviet and China would be annulled until a conference could convene. That made all treaties, border relations, and commercial relations dependent on the upcoming conference. That, in turn, gave the Soviets time to turn to Zhang Xueliang in Manchuria, who was the strongest warlord there. He had control of the Mukden government in the city now known as Shenyang. The Soviets were the first to propose joint management of the CER with the Chinese, but Zhang stood in the way of the joint management. The Soviets decided to make a deal with Zhang. On May 31, 1924, Lev Karakhan and Dr. V. K. Wellington Koo, the Minister of Foreign Affairs for the Republic of China, signed a Sino-Soviet treaty that included multiple articles, which played right into the Soviets' hands because Article V it stated that "the employment of persons in the various departments of the railway shall be in accordance with the principle of equal representation between the nationals of the Union of Soviet Socialist Republics and those of the Republic of China." The Soviets added, " In carrying out the principle of equal representation the normal course of life and activities of the Railway shall in no case be interrupted or injured, that is to say the employment of both nationalities shall be in accordance with experience, personal qualifications and fitness of applicants." While negotiations had been concluded with the Chinese, the Soviets turned to make a deal with Zhang. They promised him full control of choosing the Chinese officials who would be on the board in the joint Chinese-Soviet management of the CER, which would give him half control of CER. On September 20, 1924, he signed the Secret Agreement without knowing the Chinese government had signed the Secret Protocol earlier in the year. Since the CER was originally controlled by the Soviets, most of the positions would be under Soviet control. The Soviets then claimed they should keep majority control because any other solution would interrupt or injure the railway. The Soviets were also the puppet master of the President for the CER. They regained majority control of the CER by playing the secret protocols off each other and by outmaneuvering the Chinese. The Soviets allowed the Chinese to think they were adding workers loyal to their government. However,