全面抗戰初期,國民政府本著"世界戰爭"和"國際解決"理念,其外交兼有戰時特點和戰前慣性,側重聯英、聯蘇。1938年10月起,美日在亞太沖突加劇,美國對援華制日開始抱積極態度,而英國在歐洲持續受壓,不斷對日本妥協。國民政府開始調整外交中的英美主從關系,戰時外交呈現英蘇美并重的多元化格局。1939年8、9月間,蘇德締結互不侵犯條約,歐戰爆發。為加入英法陣營,使中日戰爭與歐戰同時解決,國民政府一度考慮對德國宣戰或撤使,但在國際局勢極不明朗的情形下,決定不公開地選擇"英法路線"。在此過程中,美國因素起了至關重要的作用,國民政府不僅以美國作為決定歐戰政策的"標準",更將之確定為外交的新重心。1939年后,美國明顯加大援華制日力度,呼應及鞏固了國民政府"首重美國"的外交決策,也使英蘇兩國相應退居中國外交"第二線"。

In the early stages of the full-scale Anti-Japanese War,influenced by the ideas of "world war"and "international resolution,"the Nanjing national government had both wartime characteristics and prewar inertia in the diplomacy,focusing on forming alliances with Britain and the Soviet Union.From October 1938 on,conflict between the US and Japan in the Asia-Pacific intensified,and the US began to take a positive role in aiding China to resist Japan.However,being then under constant pressure from Europe,Britain kept compromising with Japan,leading the national government to start reordering the relative primacy of its relationship with Britain and the US.Wartime diplomacy presented a diversified situation in which Britain,the Soviet Union and the US were of equal importance.During August and September 1939,Germany and the Soviet Union signed a non-aggression pact and war erupted in Europe.To join the British and French camp and at the same time find a joint solution to the Sino-Japanese War and the war in Europe,the national government at one time considered declaring war on Germany or recalling its ambassador.However,given that the international situation was far from clear,it decided to align with Britain and France,but without making this public.The US factor was of vital importance in this course of action.It was not only the national government’s standard for its policies on the European war but also its new diplomatic focus.After 1939,the US significantly increased its aid to China,cooperating with and consolidating the national government’s foreign policy of putting the United States first.Correspondingly,Britain and the Soviet Union fell back to the"second front"of the government’s foreign policy.