system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How has the suit become such an international standard of formalwear/men's fashion, to the point where in his official portrait Kim Jong Un can be seen wearing one?
gpt
The influence of European nations. It became popular through the 20th century in Europe. It became popular as formal wear as official policy in Europe's former colonies (US, South America, and Latin America) imported the design, while their colonies in Asia and Africa adopted/had European fashion preferences forced upon them.

Korea never was an European colony. However, it was a a colony of Japan (from 1910 to 1945) after Japan had rapidly industrialized and "westernized" (which included colonial ambitions) after Commodore Matthew Perry had forced Japan open to trade with the threat of Battleships in 1852. So, Japan adopted Western Fashion, and the Koreas adopted it as well.