Which Asian states managed to maintain their sovereignty in the nineteenth century?

- Japan: Japan was able to maintain its sovereignty by undergoing rapid modernization and industrialization, known as the Meiji Restoration, which allowed it to resist Western pressure.

- Thailand: Thailand was able to maintain its sovereignty through a combination of diplomacy and modernization.

- China: China was able to maintain its sovereignty despite a series of defeats in the Opium Wars and the Taiping Rebellion, as well as foreign incursions.

- Korea: Korea was able to maintain its sovereignty until 1910, when it was annexed by Japan.

- Bhutan: Bhutan was able to maintain its sovereignty through a series of treaties with Britain, which recognized Bhutan's independence.

- Nepal: Nepal was able to maintain its sovereignty through a series of treaties with Britain and China, which recognized Nepal's independence.