民國二十年「九‧一八」事變，曾使國府陷入「和則政府必推倒於內，戰則必推倒於外」的兩難局面。延至翌年「一‧二八」之役，前後四個多月間，決策過程的遲迴卻顧，形成了近代對日關係史上，最受批評的課題之一。本文就此提出個人看法，認為此一時期國府外交政策，實際處於某種青黃不接的「空窗」階段；表現而外，就是不穩定的「嘗試─錯誤」特徵。詳究其因，主要來自政治體系的種種問題：內則派系不和、共識難產；外則無法維持「自主性」功能，有效扮演「守門員」角色。以致「國內因素」慣常凌駕「國際因素」，成為左右決策的真正關鍵；外交政策的產出，自然缺乏應有的穩定性與一貫性，動輒陷入週邊環境的衝突當中。 故本文嘗試改以「政策選項」的概念，取代一般以「實力人物」為主線的研究途徑；並將此一「嘗試─錯誤」過程，劃分為三個時期：「不抵抗政策」延續時期、事變擴大時期與孫科主政時期。透過決策者「為」與「不為」的各種選項，凸顯國府對國內、對日本、乃至對國聯的複雜困境與政策考量。最後歸結於對此一主題之現有研究，提出筆者的管見與修正，以期考察反思，有待日後超越。

The Mukden Accident of Sept. 18, 1931, compelled the Kuomintang government into facing a dilemma of war-and-peace. Because of its own weakness in policy-making autonomy and “gatekeeper” function, KMT government hesitated as to how to reply to the invasion of Japanese troops for more than four months. This hesitation and the whole policy-making process has become a controversial issue in Sino-Japanese relations research. In this article, the author used the President Chiang Kai-shek File (the former “Ta-Chi File”「大溪檔案」) to reconsider this process, and to put forth some new analyses. In the author's opinion, this period of hesitation could be regarded as a “trial and error” process; although the Nanking government had tried many alternatives during this four months period, but never could get the consensus of factions in the KMT political system. In result, the policy outcomes tended to be ambiguous and oscillatory. Until the Shanghai campaign of 1932, this situation was allayed at last by the cooperation of Chiang Kai-shek and Wang Ching-wei (汪兆銘).