In 1922 the Kuomintang-warlord alliance in Guangzhou was ruptured, and Sun fled to Shanghai. By then he saw the need to seek Soviet support for his cause. In 1923 a joint statement by Sun and a Soviet representative in Shanghai pledged Soviet assistance for China's national unification. Soviet advisers—the most prominent of whom was an agent of the Comintern, Mikhail Borodin—began to arrive in China in 1923 to aid in the reorganization and consolidation of the Kuomintang along the lines of the Communist Party of the Soviet Union and establish the First United Front. The CCP was under Comintern instructions to cooperate with the Kuomintang, and its members were encouraged to join while maintaining their party identities to form a "bloc within."