The series of unequal treaties that imperialist powers established with China contributed to the Qing Dynasty's demise by causing nationalist and revolutionary uprisings. As the uprisings grew in size and number, they forced the Dynasty, specifically the young Emperor Xuantong, to relinquish its power.
Dr. Sun Yatsen was the most prominent nationalist leader in China. He established four basic principles for the new Republic: elimination of special privileges for foreigners, national reunification, economic development, and a democratic republican government based on universal suffrage. Although opposed to communist ideas, he created an alliance between his party, Guomindang, and the CCP which began to establish a new political system.
The Chinese youth looked to the USA and Europe for ideas and wanted the two to help reestablish Chinese sovereignty by nullifying the unequal treaties. Instead, they encouraged the increasing level pf Japanese interference in China.
Japan was a small country in need of raw materials, which were abundant in Chinese lands.
The members of the May Fourth Movement protested against foreign interference, especially Japanese, in China. They wanted to rid the country of imperialism and instead establish national unity.
The Chinese Communist Party was organized in 1921 in Shanghai. The new political party looked to the Soviet system of government for guidance and combined Lenin's ideas with those of Karl Marx to form a new form of communism.
Jiang Jieshi and the Guomindang party turned against their former communist allies because unlike the communists, they did not want to start a social revolution in addition to the political one already in progress.
After the Guomindang party seized power, they faced three major problems. The nationalists only controlled party of China; the rest was under the rule of warlords. The communists still posed a major threat. Japan was becoming increasingly aggressive towards China.
Mao believed that the peasant discontent present in China was a key part of. China and that it deserved communist support. He came to rely on the support of the peasantry to establish the communist party in a predominantly agrarian society.
The encouragement of peasant rebellions by the CCP led to the downfall of of feudal landlords, whose power was then taken by the combined force of the peasants and the CCP.