I don't know if this has already been posted (the search function didn't give useful results), let's say the Chinese Communist Party (CCP) loses the war, with any PoD you want, and the Republic of China (ROC) comes around under Chiang Kai-Shek's party? How would China be by the 21th century and how does this affects the world?
About China itself, I've done some research, some argue that China could have modernized and expanded its economy much earlier, without suffering the catastrophic policies of Mao's regime; also, it would be much more open to Western influence (while Communist China was notoriously isolationist) and preserve its culture (a mark of nationalism, indeed, even if the government might tries to distance the "national ideals" from the legacy of Qing Dynasty).
On the other hand, it seems the Kuomitang's administration was inefficient and corrupt, Chiang Kai-Shek himself was seen by the general populace as a corrupt bureaucrat; while its supposedly progressive and centralizing policies actually allienated important politico-economical groups. With this in mind, perhaps the post-Civil War period, instead of a gradual rebuild sparks even more unrest in the midst of an exhausted country.
Regarding geopolitics, my guesses are that China's inclusion on the Western sphere of influence seriously impacts the Soviet policy regarding proxy warfare, as the URSS becomes less inclined to intervene in East Asian affairs, and becomes even more isolationist, focusing on Eastern Europe and Central Asia. In this scenario, China probably won't get nuclear so soon, as they received nuclear technology from the Soviets.
The Korean War might become a decisive US victory, while the Nationalist Chinese will remain hostile to Japan, and will certainly fear its swift recovery in the second half of the century. Also, would the USA be so inclined to invest in Japan's postwar recovery if China had not become communist and remained in friendly terms with the western powers?