The 1939–40 Winter Offensive was one of the major engagements between the National Revolutionary Army and Imperial Japanese Army during the Second Sino-Japanese War, in which the Chinese forces launched their first major counter-offensive on multiple fronts. Although this offensive failed to achieve its original objectives, some studies have shown that this operation came as a heavy blow to the Japanese forces, as well as a massive shock to the Japanese military command, which did not expect the Chinese forces to be able to launch an offensive operation on such a large scale.