These countries disappeared in the 21st Century in order. This includes countries not recognized by the UN:
Also Known as Serbia and Montenegro after 1992, Yugoslavia was founded in the aftermath of the First World War. During World War 2, the country was taken over by the Nazis and was replaced by the Independent State of Croatia with Macedonia and Serbia being separate puppet states. After the end of the Second World War, Yugoslavia's borders were restored under communist rule; however, the country remained neutral during the cold war. After the fall of the soviet union, Croatia, Slovenia, Macedonia, and Bosnia broke away from Yugoslavia. In 2006, the final blow was dealt to Yugoslavia when Montenegro seceded.
Reunified with Cyprus in 2017
reunified with Somalia in 2024 after the defeat of Al Shabaab
Korea was Split along the 48th parallel in the aftermath of WW2. The border was changed slightly in the aftermath of the korean war. Until the mid 1970s, North Korea's economy actually fared better than the south's. By the 1990s, the soviet union, the north's economy was worse off than the south and with the collapse of the soviet union, economic growth stagnated and a famine led to the death of 2 million. This didn't stop the country from developing a nuclear program and performing their first test in 2006. In 2025, the state's integrity was so weak that it collapsed and got annexed by the south.
Similar to north korea, Pakistan's GDP per capita was higher than India's until 2003. As time went by, Pakistan was overshadowed by its much bigger Hindu neighbor. While this was going on, tensions between the two nations cooled down. In the 2030s the nation's economy was so weak that it had little choice but to merge with india.
People's Republic of China
The PRC was founded in the aftermath of the chinese civil war. It started out with extreme socialism then began adopting free market ideals in the 70s. In the 2010s, many people believed that China would be the world's next superpower starting in 2030. However, the housing bubble in China led to an economic recession in 2021. This put construction projects on hold and led to a high unemployment rate. The crisis had a negative effect on the US since it was China's largest importer. Many african countries suffered due to no longer receiving imports from the country and the amount of exports going to china also decreased. At that moment, the chinese economy had slown down to a grinding halt. Although China eventually recovered from the crisis, their economic growth would never be the same ever again. In the 2040s, the chinese president was making democratic reforms. However, he was overthrown in a coup which led to a destructive civil war which claimed 60 million lives. After the war was over, Taiwan's government merged with the mainland, officially pronouncing the end of the PRC. Tibet was granted independence.
Due to rising sea levels, the maldives were abandoned and most of the inhabitants fled to either India or bangladesh
United Arab Emirates
In the aftermath of the great arab war, the UAE split up into emirates.