The Treaty of Kangwha, signed in 1876, was a pivotal agreement between Japan and Korea that had long-lasting implications for East Asian geopolitics. The treaty emerged from Japan's desire to expand its influence in East Asia following the end of its period of isolation and its subsequent modernization efforts. Pressure from Western powers led Japan to seek treaty agreements with neighboring nations, and Korea was a significant target due to its historical tributary relationship with Qing dynasty China.

The treaty's provisions granted Japanese nationals extraterritorial rights within Korea, meaning they were subject to their home country's laws rather than Korean laws. Additionally, the agreement led to the opening of three key Korean ports—Incheon, Wonsan, and Busan—to Japanese trade. This not only facilitated increased commercial interactions between Japan and Korea but also marked the beginning of Korea's gradual economic dependency on Japan. A significant outcome of the treaty was the termination of Korea's status as a tributary state of Qing China, effectively altering the balance of power in the region.

The signing of the Treaty of Kangwha can be seen as a culmination of both Japan's ambition and Korea's vulnerability during a time of global shifts in power. While it represented Japan’s growing assertiveness, it also highlighted Korea’s diminishing autonomy, as foreign influences began to tighten their grip on its sovereignty. This event was foundational in setting the stage for future conflicts and treaties in the region.