191 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje LT. COL. YANAGAWA HEISUKE AND THE DEMARCATION OF PREKMURJE: A Japanese Account of the Yugoslav-Hungarian Border Commission’s Activities in 1921–1922 Boštjan Bertalanič “World War I revolutionized the political configuration of Europe. Nowhere was this more evident than in the Balkans, …” 1 1 See note 9. 192 The 20 th Century Through Historiographies and Textbooks INTRODUCTION The present article proposes to reexamine Japan’s role in the wider context of post-World War I European politics. It situates Japan in the heart of the postwar European territorial and political realignment and aims at presenting how Japan participated in the political reorganization of Europe after the war. The article aims particularly at introducing a new discourse on Japan’s role in the reshaping of the postwar political map of Europe. More specifically, it looks into the work of the Yugoslav-Hungarian Border Commission which was established by the Treaty of Trianon (1920). This treaty was part of a system of peace covenants that were concluded after the Paris Peace Conference (1919) and represents one of the stepping stones towards the new Wilsonian world order. These peace treaties prescribed new frontiers and redefined the territories of the old and new states. They also established special border commissions that were mandated to trace the frontiers on the ground. As a member of the Allied powers, Japan was a sign- ing party to the Treaty of Trianon, and as a member of the Yugoslav-Hungarian Border Commission also participated in the process of fixing the border between Hungary and the newly formed Yugoslav kingdom. 2 The main reason for choosing this commission as a case study is the avail- ability of primary sources at the National Archives of Japan (NAJ) which docu- ment the work of the Commission. 3 This offers a unique opportunity for study - ing the Yugoslav-Hungarian Border Commission’s work from a non-European perspective. Furthermore, the demarcation of the Yugoslav-Hungarian border was one of the central pillars for the stabilization of Europe in the aftermath of World War I, which in turn contributed to the establishment of the new regional balance in the Balkans. 4 In this regard, we can argue that Japan participated in the political stabilization efforts in Southeast Europe and in fixing national ter- ritorial landmarks which defined national identities in the region. The Yugoslav-Hungarian Border Commission also established the frontier that today divides Slovenia and Hungary. After the war, the predominantly Slovene region of Prekmurje, which was historically under the political tute- lage of Hungarian authorities, became part of the Slovene national territory. This was an important step in the historical consolidation of Slovene nationhood and 2 Lederer, Ivo J.. Yugoslavia at the Paris Peace Conference – a Study in Frontiermaking. New Haven: Y ale University Press, 1963, p. 3. 3 Until 1929 ‘Yugoslavia’ was known as the ‘Kingdom of Serbia, Croatia and Slovenia’. Because the terms were already widely used during World War WI ‘Yugoslavia’, ‘Yugoslav kingdom’ and the ‘serbo-Croat-Slovene State’ will be used interchangeably throughout the article. 4 All sources from the NAJ used in the paper are available in digitalized form from the Japan Center for Asian Historical Records (JACAR), https://www.jacar.go.jp. 193 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje associates Japan not only with the postwar stabilization of the region, but indi- rectly also with the nation building processes in Southeast Europe. The central goal of the article is to present an account of the Yugoslav- Hungarian Border Commission’s activities in Prekmurje, based on official re- ports by the Japanese Commissioner Lt. Col. Yanagawa Heisuke. 5 Most of his reports are commentaries, summaries or translations of commission meetings and deliberations and are written in Japanese and French. As a narrative frame- work, I supplement his reports with information from the official records of the British Representative and Yugoslav-Hungarian Border Commission Chairman Lt. Col. Cree. His records offer one of the most comprehensive accounts of the Yugoslav-Hungarian Commission’s work and are an indispensable aid in any attempt to recount the events surrounding frontier making in the Balkans after the Paris Peace Conference. 6 The paper follows a simple structure. After this brief introduction, it ex - plains the international legal framework for establishing the border commis- sions. It then proceeds with the description of the Yugoslav-Hungarian Border Commission’s structure and work procedures. The fourth section and the cen- tral part of the paper offers an account of the Commission’s activities based on the reports and official memos of Lt. Col. Yanagawa which are, where necessary, supplemented with information from the Cree report. The paper ends with an overall assessment of the study and charts some possible future research trajec- tories. THE TREATY OF TRIANON AND THE YUGOSLAV-HUNGARIAN BORDER COMMISSION The border disputes between Hungary and its neighbors were not resolved before the conclusion of the Treaty of Trianon. The Treaty regulated the status of the independent Hungarian state and defined its new borders with its neighbor- ing states. The Treaty also established special border commissions and tasked them with tracing the borders of the new states on the ground. Treaty article 29 explicitly defined the rules of composition, powers, decision-making and finan- cial aspects of the work of the commissions in general. Boundary Commissions, whose composition is or will be fixed in the present Treaty or in any other Treaty between the Principal Allied and 5 Vagnini, Alessandro. Drafting the Hungarian-Yugoslav Border: A Short Overview. In: Biagini, Antonello, Motta Giovanna (eds.). Empires and Nations from the Eighteenth to the Twentieth Century, Newcastle Upon Tyne: Cambridge Scholars Publishing, 2014. 6 I have followed the practice of rendering Japanese names according to local custom, surname first. 194 The 20 th Century Through Historiographies and Textbooks Associated Powers and the, or any, interested States, will have to trace these frontiers on the ground. They shall have the power, not only of fix- ing those portions which are defined as “a line to be fixed on the ground, ” but also, where a request to that effect is made by one of the States con- cerned, and the Commission is satisfied that it is desirable to do so, of revising portions defined by administrative boundaries; this shall not, however, apply in the case of international frontiers existing on August, 1914, where the task of the Commission will confine itself to the re-es- tablishment of signposts and boundary marks. They shall endeavor in both cases to follow as nearly as possible the descriptions given in the Treaties, taking into account as far as possible administrative bounda- ries and local economic interests. The decisions of the Commissions will be taken by a majority, and shall be binding on the parties concerned. The expenses of the Boundary Commissions will be borne in equal shares by the two States concerned. (Treaty of Trianon, Article 29) Article 29 was important because it empowered border commissions with the discretionary rights that enabled them to change specific parts of the bor- der where administrative or economic needs to this effect arose. However, the international borders from August 1914 were to remain unchanged and the Commission’s task was to reestablish demarcation signposts and marks. Since the Hungarian authorities protested against the terms of the Treaty, they re- ceived a ‘cover letter from the Supreme Council’ in Paris before signing it, which hinted at the possibility that changing certain segments of frontiers could be changed if recommended by the various border commissions. The contents of the ‘cover letter’ were summarized by the British delegate and Chairman of the Yugoslav-Hungarian Border Commission Lt. Col. Cree in the following words: “If, briefly, these Commissions found anywhere that the frontier caused an injustice for ethnical and economical reasons, which it was to the ge- neral interest of both countries to remove, they were to forward a re- port to the Council of Ambassadors at Paris suggesting a new line, with their reasons for an alteration, and the Council of Ambassadors would then examine the report and forward it to the Council of the League of Nations, who were to offer their good offices to the two countries with a view to arriving at a friendly solution. ” 7 7 Cree D.. Yugoslav-Hungarian Boundary Commission. The Geographical Journal 65, 2, 1925. 195 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje This discretionary power to propose alterations legally suggested the pos- sibility of Treaty modification and put the border commissions under consid- erable political pressure. However, given the fact that the cover letter was not part of the Treaty of Trianon, the Yugoslav authorities did not recognize its legal value and insisted on the strict application of the Treaty. 8 The frontier between Hungary and the Kingdom of Serbs, Croats and Slovenes was demarcated by the Yugoslav-Hungarian Border Commission. Article 43 provided the legal framework for the formation and work of this Commission. A Commission consisting of seven members, five nominated by the Principal Allied and Associated Powers, one by the Serb-Croat-Slovene State, and one by Hungary, shall be constituted within fifteen days from the coming into force of the present Treaty to trace on the spot the fron- tier line described in Article 27 (2), Part II (Frontiers of Hungary). (Treaty of Trianon, Article 43) Besides the Treaty provisions and the Supreme Council’s cover letter, the Ambassadors’ Conference issued in July 1920 ‘General instructions for the Delimitation Commission for Hungary’ and further defined the details of the Commission’s work: “They will have full powers, not only as regards the determining of those sections of the frontier which are defined as ‘lines to be determined on the ground’ but if one of the States concerned applies for this to be done and if the Commission considers it desirable, they will further have power to revise sections of the frontier which are defined by administrative boun- daries, except in the case of the international frontiers which existed in August 1914. In regard to these international frontiers the duties of the Commissions will be confined to the verification of the boundary posts or marks. They will even be empowered – apart from cases in which they are authorized to do so by special provisions – to alter the allocation of localities referred to by name in the Treaty, provided that such alterations are of trifling importance and that the Commission is unanimous on the matter. They will endeavor in all cases to conform as closely as possible to the definitions of the frontier given in the Treaty, taking count as far as practicable of administrative boundaries and local economic interests, but without regard to any national, linguistic or religious considerations. ” 9 8 Ibid., p. 92. 9 “The Delimitation of the of the Frontiers between Hungary and the Adjoining States. Position on Question, June 29, 1922, ” (League of Nations: Memorandum by the Secretary General, C.428.1922. VII, 1922). 196 The 20 th Century Through Historiographies and Textbooks III. THE YUGOSLAV-HUNGARIAN BORDER COMMISSION – PRELIMINARY MEETINGS AND METHOD OF WORK The Treaty of Trianon constituted four border commissions and the Yugoslav- Hungarian Commission was the main body in charge of defining the new fron- tier between Hungary and the Yugoslav Kingdom. The Commission met for the first time in Paris in the rooms of the Geographic Service of the French Army on August 1, 1921. During this first meeting, the British Representative Lt. Col. Cree was appointed as the Chairman and the overall organization of the Commission was determined. 10 Lt. Col. Cree described the preliminary preparations in the following manner: “At the first meeting the President was elected and the organization of the Commission was then settled. This is generally about the same in all commissions, the French, Italian and English Delegations consisting of a Commissioner and two N.C.O.s as clerks. It is laid down that one should be a topographer, but only in the English delegation had any one any technical knowledge. The Japanese Commissioner had a Japanese secretary and a French interpreter. The interested Commissioners were at liberty to organize their delegations to suit the varying problems that might arise. Further, a Secretariat was appointed to the Commission, this consisting of a French captain as secretary and a clerk, also French. ” 11 Besides Lt. Col. Cree, the other Commission members were Col. Luigi Valvassori from Italy, Lt. Col. Marminia from France, Lt. Col. Heisuke Yanagawa from Japan, Col. Vassel from Hungary and Col. Vojin Čolak-Antić represent- ing the Kingdom of Serbs, Croats and Slovenes. 12 The Commissioners selected Varaždin (Croatia) as their first headquarters and decided to work from west to east. As the work progressed, the headquarters moved along the frontier and al- ternated between Hungary and Yugoslavia. Transportation was provided by the country in which the Commission was working at that specific time, however it 10 Yanagawa, Heisuke. Hungary Slovenia Border No.1: Starting Field Work and Travel by Committee Member, August 5, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040348700 National Institute for Defense Studies of the Ministry of Defense), p. 3. 11 Cree, Yugoslav-Hungarian Boundary Commission, p. 93. 12 Lt. Col. Heisuke Yanagawa was born in 1879 in Nagasaki Prefecture. He graduated from the Army Cadet College in 1900 and served as a First Lieutenant in the Russo-Japanese War of 1904–05. In 1920, after the end of W orld W ar I, he was sent to Europe to serve as a Japanese military attaché at the League of Nations. It is during this period that he was designated as the Japanese Commissioner in the Hungarian-Yugoslav Boundary Commission. After returning back to Japan he was appointed Vice Minister of Army. From 1940 he became the Minister of Justice in the second Konoe administration, and later on served as Minister of Home Affairs. He died in 1945. 197 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje proved to be one of the most challenging aspects of the Commission’s work and Commissioners often complained about it. 13 The border was arranged in six sections: “the first from the Austrian frontier to the junction of Lendava and Mura, the second from this point to the railway bridge over the Drava at Barcs, the third from this bridge to the point where the frontier leaves the Drava, the fourth between the Drava and Danube, the fifth between the Danube and Tisza, and the sixth from Tisza to the Rumanian frontier.” 14 The Commissioners left Paris on August 11 and after a round of courtesy calls to the capital cities began their work in Varaždin on August 23. 15 However, before commencing with the field work, the Commissioners agreed to conduct a general survey of the entire border in order to determine where the Treaty must be strictly applied and in which sections a request to modify it might be made to the League of Nations. Where they met no opposition, it was decided to fix the border at once, following the original instructions. In case of an appeal from any of the concerned parties, all proposals with their implications for the entire bor- der had to be considered before any official request was forwarder to the League of Nations. Lt. Col. Cree described the method of work as follows: “We resolved to fix definitely at once the frontier as laid down in the Treaty, working in accordance with the original instructions to Boundary Commissions, but before we started our inquires on the ground we de- manded from the Interested Commissioners, not only their propositions for the Treaty Line itself, but also any propositions that might be the su- bject of an appeal to the League of Nations. In this manner we were able, during our inquiries on the Treaty Line, to keep the other question also in our minds, so by the time we had decided on the line the frontier should follow under the Treaty, we had already a great deal of valuable informa- tion for the further proposition. ” 16 After the preliminary reconnaissance work, the Hungarian and Yugoslav Commissioners prepared and submitted their proposals for modifications of the border. These proposals normally addressed the ethnic and economic con- ditions of the portion of the border under consideration, and were supported by maps and various pleas from local chambers of commerce, large property owners, or factory owners. A meeting was then called where the Commissioners discussed possible solutions and when needed requested additional information. 13 Cree, Yugoslav-Hungarian Boundary Commission, p. 93. 14 Ibid. 15 Y anagawa, Hungary Slovenia Border, p. 2. 16 Cree, Yugoslav-Hungarian Boundary Commission, p. 95. 198 The 20 th Century Through Historiographies and Textbooks During the meetings, they also devised a program for any further inquiries on the ground. The main idea was to allow delegations from all concerned commu- nities to express their opinions, and a meeting held in Hungary in the morning was balanced by a meeting in Yugoslavia in the afternoon. The local authorities were informed a week in advance about the dates of the meetings, and the local communities then had to elect their delegations in which all minorities had to be represented. These delegations were headed by the mayor and consisted of six delegates. In this way the Commission was able to obtain evidence from both sides on the same day. In certain cases, they also provided questioners, who were cross checked at direct public hearings by the Commission Chairman. Public hearings were held at locations close to the villages. These were often situated in remote areas and access by cars was rather challenging. At each hearing, about four to six delegations were heard out. By the time the inquires on the ground were finished, further Commission meetings were convened to deliberate pro- posals in the light of the knowledge gained through hearings and surveys, and attempts would be made to reach a consensus among the Commissioners. Once the agreement was reached, the frontier was marked in red ink on a 1/75,000 map and signed by all Commission members. In the final stage, the border was demarcated by pickets and both Hungarian and Yugoslav governments were of- ficially given fifteen days’ notice to occupy the line. 17 The Commission continued to work until May of 1924, when the Commissioners gathered for the last meet- ing in Zagreb to draft their final report. 18 THE YUGOSLAV-HUNGARIAN BORDER COMMISSION AND THE BORDER BETWEEN HUNGARY AND SLOVENIA As planned, the Commission began working on the first section of the Yugoslav-Hungarian border in August 1921. This part of the border, approxi- mately 100 km long, was also known as section A and represented the Treaty line dividing Hungary and Slovenia in the region of Prekmurje. 19 What made this section interesting is that it became the subject of the first proposal for bor- der modification to the League of Nations. It also marked the beginning of the 17 Ibid., pp. 96–98. 18 Vagnini, Drafting the Hungarian-Yugoslav Border, p. 317. 19 Prekmurje represents a linguistically and culturally distinct region in the Northeast of Slovenia. It was under Hungarian rule from the 11 th century and after the end of World War I, the region was captured by Yugoslav troops and incorporated into the newly formed Yugoslav kingdom. After the conclusion of the Treaty of Trianon the whole of the district was demanded back by Hungary; however since the population was predominantly Slovene, Hungary had difficulty in supporting its claims. 199 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje Commission’s work and in many respects established work procedures that de- termined Commission activities in other border sections later on. During the first month of work, incidents and complications were common. As soon as the Commissioners were about to reach Varaždin, the Yugoslav au- thorities arrested the Hungarian courier and confiscated his official documents. Later, this became known as the Kotoriba Incident, named after the Croatian town of Kotoriba where the matter took place. Hungary protested and accused the Yugoslav side of violating diplomatic protocol and demanded that they im- mediately reestablish train connections and allow the free passage and inviola- bility of Hungarian diplomatic bags. 20 In the beginning of September 1921, as the Commission was preparing to trace the border, Hungarian representative Col. Vassel tabled the first of his sev- eral proposals for border modification. He submitted a substantial memoran- dum, which demanded the return of the whole region to Hungary on ethnic and economic grounds. Citing economic and ethnic reasons, the Hungarian au- thorities argued that Prekmurje was not a distinctive historical, linguistic and politico-economic region as the Yugoslav side claimed. The memorandum also argued that the majority of the people in Prekmurje opposed their inclusion into the Yugoslav state. 21 Field work began on September 5, 1921 when Commissioners surveyed and provisionally fixed the tripoint (tri-border) between Austria, Hungary and the Yugoslav kingdom – also the starting point of the border between Hungary and Yugoslavia in Prekmurje. 22 On this occasion, Lt. Col. Cree commented that the Commissioners were not able to arrange a meeting with the Austro-Hungarian 20 Yanagawa, Heisuke. Hungary Slovenia Border No. 5: Submiting Document from Hungariam Committee Member, August 30, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040348900 National Institute for Defense Studies of the Ministry of Defense). 21 Hungary Slovenia Border No. 9: Sending Monthly Operating Report, September 5, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349000: National Institute for Defense Studies of the Ministry of Defense); Hungary Slovenia Border No. 12: Sending Appendix of Second Proposal from Hungarian Committee Member, September 8, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349100: National Institute for Defense Studies of the Ministry of Defense); Hungary Slovenia Border No. 13: Sending Appendix of Second Proposal from Hungarian Committee Member, September 9, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349200: National Institute for Defense Studies of the Ministry of Defense). 22 Hungary Slovenia Border No. 14: Report on Starting Field Work and Sending Map, September 16, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349300: National Institute for Defense Studies of the Ministry of Defense); Hungary Slovenia Border No. 18: Sending Monthly Operating Report and Report on Progress, September 30, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040350200: National Institute for Defense Studies of the Ministry of Defense); Hungary Slovenia Border No. 26: Sending Minutes of Committee Meeting, October 17, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349400: National Institute for Defense Studies of the Ministry of Defense), 11. 200 The 20 th Century Through Historiographies and Textbooks Border Commission in order to fix the common point definitely, and had to wait until the following May when they were working at Szeged, at the opposite end of the frontier. 23 From September 19, 1921 the Commission began a series of public hearings, which were meant to help better understand local economic relations and the ethnic structure of the communities in the region, in part due to the Hungarian demands for the restitution of the whole region. This was supposed to help the Commission establish if there was really any need to modify the Treaty. 24 Also it was through these public hearings that the Commission exercised its discretion- ary power to propose treaty amendments in the most explicit way. The first two days of Commission ground inquiries were followed by pro- Hungarian demonstrations on the Yugoslav side of the frontier. Several demon- strators were arrested by the military and police. There were, however, no coun- ter demonstrations, which suggested that they were at least in part sponsored by the Hungarian side. In response, the Yugoslav authorities took severe counter measures which eventually became the subject of an official complaint by the Hungarian Commissioner. The Commission inquired into the charges and es- tablished that they were exaggerated, but that the measures were justified by the necessity of maintaining public order. 25 Probably one of the biggest incidents during the Commission’s stay in Prekmurje was the arrest of the Japanese Commissioner Lt. Col. Yanagawa himself by the Yugoslav police. The incident happened towards the end of the Commission’s work in November. Yanagawa was suddenly stopped by a Yugoslav police officer and taken at gunpoint to the nearby police station where he was interrogated. Since his official car had no flags or other signs attesting to his diplomatic status, the local police apparently did not recognize him as a member of the Yugoslav-Hungarian Border Commission. Although his predicament was eventually solved, he was outraged by the entire matter, especially the attitude of the police officers involved, and strongly protested to the Yugoslav authorities. 26 23 Cree, Yugoslav-Hungarian Boundary Commission, pp. 98–100. 24 Yanagawa, Heisuke. Hungary Slovenia Border No. 20: Sending 5 th Proposal from Hungarian Committee Member and Other Two Items, October 4, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349900: National Institute for Defense Studies of the Ministry of Defense). 25 Hungary Slovenia Border No. 27: Report on Work Progress, October 20, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040349500: National Institute for Defense Studies of the Ministry of Defense), pp. 4–5; Cree, pp. 100–01. 26 Y anagawa, Heisuke. Hungary Slovenia Border No. 29: Report Details of Illegal Act by Slovenian Police Officer, November 7, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040350500: National Institute for Defense Studies of the Ministry of Defense); Hungary Slovenia Border No. 31: Additional Report on Police Officer’s Illegal Act, November 8, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040350600: National Institute for Defense Studies of the Ministry of Defense). 201 Bertalanič: Lt. Col. Yanagawa Heisuke and the Demarcation of Prekmurje Public hearings were held through September and October 1921. 27 From these meetings, the Commission learned that in the north and north-east the regional administrative boundaries of Murska Sobota (Muraszombat) corre- sponded very closely with the regional economic boundary. South of this line, the communities were economically dependent on Murska Sobota or other eco- nomic centers close by. However, a small group of villages situated towards the north of this line gravitated towards Monošter (Szentgotthard). For these reasons, the Commission decided to recommend to the League of Nations that six communities belonging to Monošter and twenty predomi- nantly Hungarian villages north of Lendava should be returned to Hungary. 28 Following the stipulations of the ’supplementary instructions for the delimita- tion commissions for Hungary’ approved by the Conference of Ambassadors on June 3, 1921, the Commission then compiled its final report proposing a modi- fied border. 29 They delivered the report to the League of Nations at the end of November 1921, 30 hoping that it would be accepted. However, a year later the Conference of Ambassadors rejected the proposal with the following ruling: “The Conference of Ambassadors came to the conclusion that, in these circumstances, the proposal put forward by the Frontier Commission co- uld not be utilized, and decided that the delimitation of the Hungarian and Serbo-Croat-Slovene frontier should be carried out in conformity with the Treaty of Trianon, and the instructions at present in force. ” 31 CONCLUSION After the conclusion of World War I, Europe faced one of the largest political and territorial reconfigurations in its modern history. This paper has attempted to place Japan right in the middle of these events. It has explained how Japan was part of the peace system in Europe, not only by mere participation in the Paris Peace Conference, but also by being represented and actively involved in the territorial settlements that came out of the peace treaties. For example, the 27 Hungary Slovenia Border No. 26: Sending Minutes of Committee Meeting, October 17, 1921, pp. 12–27; Hungary Slovenia Border No. 36: Sending Minutes of Committee Meeting November 14, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040350800). 28 Cree, Yugoslav-Hungarian Boundary Commission, p. 102. 29 League of Nations,The Delimitation of the Frontiers between Hungary and the Adjoining States. Position on Question, June 29, 1922. 30 Yanagawa, Heisuke. Hungary Slovenia Border No. 47: Sending Proposal to League of Nations and Report on Progress, November 26, 1921. In: Documents on peace treaty No.10, 1918, Ministry of Army (JACAR Ref. C08040350300: National Institute for Defense Studies of the Ministry of Defense). 31 Delimitation of the Frontiers of Hungary. League of Nations: Note from the Secretary General, C.751.M.455.1922.VII, 1922. 202 The 20 th Century Through Historiographies and Textbooks Yanagawa reports place Japan right in the middle of the Allied efforts to stabilize the Balkans. The Serbo-Croat-Slovene State rising up on the rubble of the col- lapsed Habsburg empire quickly formed into one of the central dynamic forces of the new regional order. Especially in this regard, fixing the Yugoslav-Hungarian frontier became a condition sine qua non for regional stability. Without doubt, the Yugoslav-Hungarian Border Commission played a central role in this pro- cess. This was obvious already in Prekmurje, where the basic work procedures of the Commission were set and tested. Furthermore, Yanagawa’s participation in the demarcation process of Prekmurje represents a link between Japan and the post-World War I nation building process – not just in Slovenia, but in Southeast Europe in general. A considerable amount of still unread records written by Japanese representatives who were active in other border commissions in the Balkans also attests to that. Any future effort to better comprehend and systema- tize the extent of Japan’s involvement in the wider process of post-World War I nation building in Southeast Europe should look into the work of these other border commissions. The present article was meant as a first step in that direc - tion. In this sense, I believe that documenting Yanagawa’s reports on frontier- making between Yugoslavia and Hungary in the present paper has helped to introduce the possibility of expanding and enriching the discourse of Japan’s role in the political development of Europe after World War I.