A key question on people's minds when the radioactive dust settled was 'where is Mao?'
The elusive Chinese dictator was originally assumed to be dead and theories about his survival were dismissed in the same fashion of the Hitler survival rumors- flat out denied by world governments while said governments opened secret investigations into the matter. Modern readers with any knowledge of the pre-nuclear Sino-Soviet War will recall that Mao was evacuated to a bunker in northern China before the war turned nuclear, but this was unknown to people at the time.
Despite the bunker being relatively spacious, Mao was descending further into his already significant madness.
The facility (which is now a museum) was stocked with enough provisions that the leader was able to survive for several years until the summer of 1972. At that point he emerged, officially re-establishing the People's Republic of China. Unfortunately for Chinese Communists, the United States Air Force also existed, and the threat was (to put it mildly) dealt with using what the Air Force does best- blowing up shit.
This was likely one of many factors caused Richard Nixon's massive re-election landslide of unmatched proportions that November.
Anyway, China in 1969 was (for lack of better words) a dystopia. Aid and humanitarian work was often delayed to prevent civilians from being caught in the crossfire of Operation Bringing Freedom, the poorly-disguised joint Taiwanese-US 'aid program' which was actually a operation to capture living communist party officials. Once doctors and volunteers were able to get to civilians, they found mass starvation and poor hygiene and public health conditions- in other words pre-war China, but worse.
Crop yields, already suffering at the hands of constant purges and famines, were failing altogether, showing the first effects of radiation. 1970 would be known as the 'year without summer' in reference to the temperature drop following Krakatoa's eruption in the late 19th century. Global temperatures declined by nearly a full degree Celsius, but the change was much more pronounced in China, where over 1,000 megatons of nuclear weaponry was detonated, causing a localized drop a temperature much steeper than that. Senator Jim Xi of Alaska, perhaps (like many Chinese who migrated following the Sino-Soviet war, which is understandable in retrospect) the most anti-Communist member of the body, has previously said that the summer of 1970- which were the months before he fled- he saw the sun exactly once.
The effects on nations like Japan, South Korea, and Taiwan were not very severe- both due to extensive preparations, U.S. aid, and functioning economies. South Korea was more dependent on the latter considering they had their hands full with subjugating North Korea.
It would be wrong, however, to not mention the effects on the nations of Indochina. These were nations not rich enough to prepare or strategically important enough or America to care enough to underwrite the deficit. Laos and North Vietnam were the hardest hit, with refugees streaming in. The governments tried everything to stop them, but this would only lead to a massive amount of death and murder overshadowed by the war.