Post-Nuclear (Hetalia Based)

In 1983, a Soviet submarine falsely believed that Word War Three had begun, and fired a nuclear weapon towards the United States of America. Immediately sensing the weapon, the USA sent a barrage towards the USSR and its allies. The Soviet Union, sensing the American weapons, did the same. Within hours, 75% of the Earth's population had died, huge swathes of people following in the next few months. All of the Northern Hemisphere- minus a few remote areas and South America- was surely dead, their representatives included. Revolutions rose among surviving countries, areas such as Africa falling into chaos and bloodshed without a second thought. Oceania and South America were the only areas that survived with limited damage done. The people, however, were hysterical, roughly 180 countries having fallen in the blink of an eye.

Fueled by paranoia, thousands of people who were- despite what they believed- barely in any form of danger fled to Antarctica, forming a new country: the Antarctic Union. When the first arrived, countless people died, not at all prepared for the harsh climate they faced. Humans are resilient, though, and a small pocket managed to survive the harsh cold. For two hundred years, nearly all of their essential supplies were from overseas, taken out by loans they hoped to be able to repay in the future. Finally, though, the Earth's temperature rose enough so that the Antarctic country could sustain plant growth and, well, life. Satisfied with the fact that her people can live, Maria Petronova- representative of the Antarctic Union- turns her eyes far north, to the barren nuclear wastelands of the old world. And she's not completely convinced that they all died.

Warnings:
This is not meant to be completely realistic
Swearing
A lot of your favourite characters are probably already dead
Based on Hetalia, but not all characters match its canon depiction of them