After Big City voiced support in favour of India during a China-India dispute over a piece of Jammu & Kashmir, on 18th May, 2030, China withdrew their recognition of Big City as an independent nation.
The Chinese External Affairs Ministry said that it was not a matter to comment on for Big City as neither were they involved in the conflict nor were they even close to the disputed territory. The decision was seen as rather harsh and quick but, the tense relations between Big City and China had started when the Big Citian navy had sunken a Chinese ship which illegally entered Big Citian waters (this happened 2028) and China had threatened to withdraw their recognition on many instances since then. China withdrew recognition and now it recognised Big City as an unclaimed part of Antarctica and all Big Citians holding Big Citian passports were deported as Big Citian passports were no longer accepted in China.
China used its influence to get Pakistan and North Korea to withdraw their recognition of Big City too. Soon, many countries rose in support of Big City and on 21st May, 2018, China, North Korea & Pakistan witnessed a serious backlash as the United States, Big City, India, the United Kingdom, Sri Lanka, France, Bangladesh, Afghanistan, South Korea and Japan; all withdrew recognition of these three countries.
Now, India was considered the sole legitimate government over both, India and Pakistan. Republic of China (Taiwan) was now considered as the government for China and South Korea (which already didn’t recognise North Korea) was now recognised as the sole government over all of Korea. Though, no international borders were brought down and no physical changes in terms of barriers and army took place, now maps started being printed in these countries with India-Pakistan as one (labelled as ‘India’), South Korea and North Korea as one (labelled as ‘Korea) and so on.
Neutral countries such as Germany and Russia started realising that this situation could lead to a much-dreaded Third World War. In order to stop this, the neutral forces formed a secret organisation (The Prevention Unit) which entered into negotiations with the involved countries to get them to reinstate recognition. All the countries apart from China & Big City understood the implications of this and decided to recognise the other countries and South Korea too, decided to formally recognise North Korea as an independent nation and North Korea did the same with South Korea.
Big City were keen on avoiding a war so, they decided to take the step to re-recognise China and China followed soon after as a reason for a war ended.
This is seen as close brush with another world war in world history. Slowly, tensions between the countries died down.