經過明治維新、富國強兵的變革而贏得甲午戰爭勝利的日本，藉由中國巨額的賠償而成為近代國家，並一躍成為亞洲第一強國，而戰敗的中國則陷入財政困境最後終至滅亡。二戰後不久的日本因獲得美援使得經濟復甦，工業生產也開始恢復，之後的國共內戰更促使美國改變對日政策，將大量的美援從中國轉移給日本，日本得以迅速完成戰後復興，進而免除戰爭責任、重返國際社會；中國則因為國共內戰成為兩個政權對抗的分裂國家，1950年爆發的韓戰，再因特需的帶動，使得停滯的日本工業生產再變得興盛，接著由1950年代中期左右，開始展開近20年的高度經濟成長。相對地，參戰的中國則遭受以美國為首的國際社會排擠導致經濟發展大幅落後。這三場戰爭對當時及爾後中日國勢發展有著決定性的影響。因此，本研究針對這三場戰爭對近代中日國勢的影響加以分析和探討。

After the Meiji Restoration, Japan won over victory the Qing Dynasty. With huge compensation from Qing it became a modern state, and became the first Asian power. The defeat of the Qing finally ended its rule. Shortly after World War II, due to from U.S. aid Japan made economic recovery and industrial production began to recover. The Chinese civil war had prompted the U.S. to change policy toward Japan, and transferred large amounts of U.S. aid to Japan from China. Japan then could completed it's revival quickly, getting exempt from responsibility of war and returned to the international community. China had since made secession from international society. In 1950, the outbreak of the Korean War and it's special need of supply (for the U.S. military services) had again the stagnant Japanese industrial production again. In contrast, China has suffered exclusion from the US-led economic development. Three wars had a decisive influence over japan and china, and this study will discuss their impact in details.