Final answer:
Sun Yat-Sen was unable to achieve his goals for China due to civil conflict, power struggles, and opposition from the Chinese Communist Party.
Step-by-step explanation:
Sun Yat-Sen was unable to achieve his goals for China because civil conflict and power struggles broke out in the country, particularly between the republican government and warlords. After the death of Yuan in 1916, additional provinces had broken away and a resurgence of nationalist sentiment occurred.
Furthermore, the May 4, 1919 student uprising against the Versailles Treaty, in which Japan received control of Shandong province instead of China, marked an important moment of modernization for the republic. Sun Yat-Sen formed the Kuomintang (Nationalist) Party in the same year, but his death in 1925 led to Chiang Kai-shek taking over the leadership of the party and ultimately the republic.
In addition, there were conflicting views between the nationalists and the Chinese Communist Party which also contributed to the instability and inability to achieve Sun Yat-Sen's goals.