Final answer:
By the summer of 1944, the Japanese military leadership realized that defeat was inevitable, leading to massive losses on various fronts and the resignation of Prime Minister Hideki Tojo.
Step-by-step explanation:
By the summer of 1944, the Japanese military leadership concluded that defeat was inevitable. The earlier confidence in a quick victory had faded in light of the relentless Allied advances across the Pacific and the significant losses suffered by Japan's military forces. With the defense perimeter of Japan's home islands being constantly redrawn due to losses on various fronts, and the failed invasion of India leading to massive losses, Japanese Prime Minister Hideki Tojo was forced to resign in July 1944. The inability to defend positions and maintain their conquests pointed to the grim realization that they could not win the war.