Why Mao Zedong did not sign the treaty with the USSR Sixty years ago, on December 16, 1949, negotiations between Joseph Stalin and Mao Zedong began in Moscow, which lasted 65 days. They culminated in the signing of a historic treaty of friendship, alliance and mutual assistance, which became the basis for close cooperation between the two countries in the 1950s. It was not easy for politicians, each of whom claimed to be unique, to get along with each other.