After leaving the tributary system, the Korean Empire became a focal point of rivalry between Japan and Russia.
Russian expansion through economic concessions and Japan’s response reveal the complex power struggle surrounding the Russo-Japanese War.

Although the Korean Empire withdrew from the tributary system, Russia, having placed Manchuria under its influence, advanced its southward policy by using its interests on the Korean Peninsula as leverage.
2016-01-03
The rivalry between Japan and Russia over the Korean Peninsula.
The following is based on information from Wikipedia.
Through Emperor Gojong, Russia acquired key national assets, including mining rights in Jongseong and Gyeongwon, logging rights in northern Korea, and customs authority, thereby expanding its influence on the peninsula.
Japan, however, felt a strong sense of crisis regarding Russia’s southward expansion.
This concern was rooted in events such as the Russian naval occupation of Tsushima in 1861.
Japan moved to buy back these interests and restore Korean sovereignty.
At first, Japan sought to avoid conflict through diplomatic efforts.
Russia, however, backed by its overwhelming military power, steadily increased pressure on Japan.
On February 23, 1904, prior to the outbreak of war, Japan concluded the Japan–Korea Protocol in order to enable military operations within the Korean Empire, which had declared neutrality.
After the outbreak of war, in August, the First Japan–Korea Agreement was concluded, placing Japanese advisers in charge of Korea’s finances and diplomacy and requiring consultation with the Japanese government for treaty matters.
Within the Korean Empire, the Progressive Association judged that independent reform was impossible under the old Yi dynasty system and aimed for Japan–Korea annexation.
They dispatched as many as fifty thousand personnel for railway construction and other projects, offering full cooperation to Japan during the Russo-Japanese War.
In contrast, Emperor Gojong and the old ruling elite of the Yi dynasty attempted to eliminate Japanese influence.
Even during the war, they pursued diplomacy by secretly sending envoys to Russia.
These secret envoys were discovered at sea by Japanese warships, resulting in the Korean Empire violating its treaty obligations.
This manuscript continues.