「支那駐屯軍」是日本依照「辛丑和約」的特權，派駐在中國華北的部隊，司令官多田駿於1936年3月向冀察政務委員會委員長宋哲元要求締結華北「防共協定」，他的構想源於前一年9月「多田聲明」的主張。多年來中、日學者對於該協定是否簽訂有不同的觀點，形成歷史懸案。本文耙梳中、日文檔案，研判當時雙方交涉的協定內容應有屬於軍事性質的華北「防共協定」，與屬於防共委員會組織性質的冀察「防共協定」。前者似乎已經商議達成口頭約定，但是日本陸軍省方面認為駐屯軍簽訂軍事性質協定是越權的行為，而未予同意，結果協定並未簽字；後者可能已經完成簽訂程序，因此日後駐屯軍方面可以要求宋哲元切實履行協定。多田與宋哲元沒有簽訂軍事性質的華北「防共協定」，使得駐屯軍方面無法在華北展開防共事務，加上1936年上半年中共入晉一事對日本造成震撼，日本東京方面出現與國民政府簽署防共軍事同盟的意見。1936年5月15日，駐南京總領事須磨彌吉郎參考多田的主張與辦法，草擬與國民政府交涉的「五省特政會案」。外務省方面洽詢軍部的意見，修改須磨的方案，於8月7日內閣上通過「帝國外交方針」，並於11日制定「對支實行策」，決定以國民政府為交涉主體，協議締結「防共軍事協定」與「日中軍事同盟」。「對文實行策」為空洞的「廣田三原則」找到具體可行的方法，重要的是將「防共協定」由閫外軍人的構想提升至外交層次的方案，最後成為日本的國策。為了實行這項國策，結果使得同年9月展開的中日調整國交會談，變成交涉防共議題為主的談判。駐屯軍的主張最後演變成日本國策，背景原因來自於石原莞爾主張軍部主動引導國家的「石原方針」。此一方針不僅引發九一八事變，後來亦為在華日軍所仿效，影響日本中央政府對華政策的制定。

The Japanese China Garrison Army (JCGA) in Northern China was formed in 1901 as special right of Japan according to the Boxer Protocol. In March 1936, the Army's Commander-in-chief Tada Hayao asked the R.O.C's Gen. Song Zheyuan of Hebei-Chahar Political Commission to sign an anti-communism agreement. The very idea came from his ”Tada Declaration” formed in September a year ago. For many years, this has become an unsettled historical issue and much discussion on whether the alleged agreement was actually signed. This paper tries to look into the matter in the light of numerous Chinese and Japanese documents, with a view to sorting out the confusion.It is found that there were two qualitatively different agreements. One was the ”North China” Anti-communism Agreement which was basically military-oriented. And the other was ”Hebei-Chahar Political Commission” Anti-communism Agreement, which was about the organization of anti-communism-oriented. The former had already reached the stage of an ”oral agreement.” But the Army Ministry of Japan thought the JCGA did not have the authorities to sign the agreement and denied. The later bad been properly signed, and by this the JCGA could request Gen. Song to carry out the Agreement.Because Hayao and Song did not sign the ”North China” Anti-communism Agreement, the JCGA could not do anything about the anti-communism affairs. Besides, in early 1936, Communists' entrance into Shanxi terrified the Japanese, and their government raised questions concerning the contents of the Anti-communism Agreement. On May 15, 1936, Suma Yakichiroh, the Consul General at Nanking, referred to Tada's ideas and measures and drafted the ”Proposal concerning the Administration of the Five Provinces.”After negotiating with the military authorities, the Foreign Ministry of Japan revised Suma's proposal. On August 7, the Cabinet passed the ”Japan's Foreign Policy” and formulated ”the Policy of Dealing with Chinese Issues” on the 11th. Japan was sure that the Nationalist government was the official government of China to negotiate with. Thus, the treaties of ”Anti-communism Military Agreement” and the ”Military Alliance between Japan and China” were later formulated. ”The Policy of Dealing with Chinese Issues” had finally found for the apparently empty ”the three Principles of Hirota” a concrete and plausible solution, by changing the simple-minded Anti-communism Agreement into Japan's foreign ministry's diplomatic policy. In order to realize the policy, conferences between the two nations' foreign ministries were started in September to deal with the anti-communism issues.To sum up, the policy of the JCGA finally became Japan's national policy. It was Ishiwara Kanji who suggested that the military authorities should lead the country, according to the so-called ”the Policy of Ishiwara”. This policy, which was to become the prototype for Japan's foreign policies toward China, led not only to the Mukden Incident of 1931, but also to subsequent events.