Korea
A country from which Japan imported metals, including steel, before developing its own steel production up to the 8th century.
Videos Mentioning Korea

#117 – Stanley Perlman, M.D., Ph.D.: Insights from a coronavirus expert on COVID-19
Peter Attia MD
The country where a single MERS-CoV patient infected 186 people, highlighting a confluence of bad luck despite the virus's low general transmissibility.

Bhaskar Sunkara: Socialism and Communism | Lex Fridman Podcast #349
Lex Fridman
Mentioned as a country where workers' movements created democratic systems.

How Japanese Masters Turn Sand Into Swords
Veritasium
A country from which Japan imported metals, including steel, before developing its own steel production up to the 8th century.

Politics & Power: A Conversation with Rahm Emanuel (Episode #387)
Sam Harris
Referred to in the context of trilateral diplomatic efforts with Japan and the US, and also concerning historical complexities.

Game Theory #15: The Return of History
Predictive History
Mentioned as one of the East Asian countries that are non-religious and may face future problems.