In his correspondence with Hu Shih, Chiang wrote that China was capable of withstanding six months of combat before changes in the international situation would have to end the war. This may have also caused Chiang to devote all of his best troops in the first battle of what would eventually become a prolonged war. However, while Chiang's initial assessment was overly optimistic, China continued to fight for eight more years until Japan finally surrendered after the atomic bombs were dropped on Hiroshima and Nagasaki and the Soviet invasion of Manchuria.