“I’d say those were the result of abandoning Chiang Kai-Shek. No Communist China - no Korean or Vietnam War.”
The treaty ending WWII separated Korea into a Soviet and US spheres; China had nothing to do with that. If anything, we bought Chiang 8 more years from 1937 on. While the fall of China did make it easier for the war in Vietnam to happen, the Soviets provided much of the arms (as well as pilots) to Ho Chi Minh.
Without Communist China, North Korea would have been threatened in its rear all along its 400 mile border with China. Hence, no Korean War. The Vietnamese Communist movement got the vast majority of its supplies - food, etc - as a grant from China (vs loans from the Soviets). Hence the Chinese feeling of betrayal when the Vietnamese turned against them at the end of the Vietnam War. Without a Communist China, North Vietnam would not have come into being. The French might still have decolonized, but there would have been no strong Communist faction in Vietnam. The one thing Communist movements in Southeast Asia (incl Malaysia, Singapore, Philippines, Indonesia, Vietnam, Cambodia, Laos and Thailand) had in common is that the successful ones (i.e. the ones that defeated the non-Communist governments) had a common border with Communist China or with North Vietnam. Mao fed those movements with billions in supplies* even as the Chinese people were starving to death in the tens of millions (which he viewed as a cleansing of the weak and the unfit). The problem is that apart from the Indochinese trio of Laos, Vietnam and Cambodia (border with North Vietnam), it was hard for the Chinese to get supplies to the region.
* In the 2000 time-frame, a UK-educated Chinese princeling who revealed this fact (i.e. the billions in aid) in a book about China's financial support of revolutionary movements abroad was promptly arrested and sentenced to 20 years in prison for revealing state secrets.