The signing of the Sino-Japanese Treaty of 1940 marked a significant event in the ongoing conflict between Japan and China during World War II. With increasing military pressure from Japan, the Wang Jingwei-led Reorganized National Government, which was established in Nanjing as a puppet regime, sought to legitimize itself through this agreement. The treaty allowed Japan to solidify its military occupation and control over various regions in China, reinforcing the power dynamics set in place by earlier conflicts. It also provided for collaboration between the two entities regarding military and economic matters, which further deepened Japanese influence in China.

However, the treaty was met with widespread condemnation from both the Chinese populace and the international community, who viewed it as a betrayal of Chinese sovereignty. Many saw the terms as onerous, recalling the historic humiliation of the Twenty-One Demands from 1915, in which Japan had sought extensive rights over China. The forced nature of this treaty illustrated the imbalance of power in the region, as Japan was aggressively expanding its fascist agenda throughout East Asia, taking advantage of China's political fragmentation at that time.

The treaty's most significant implications were its legitimization of Japanese authority in occupied territories and its impact on the Chinese nationalist movements that opposed Wang Jingwei’s regime. The signing did not bring stability but instead intensified resistance and fueled the desire for national unity among Chinese factions. For many, this was a rallying moment against both the Japanese occupation and the collaborationist government in Nanjing.