Editing Battle of Nanking (section)

===China's defense preparations===
[[File:I-16_in_Nanking.PNG|thumb|A Soviet-made [[Polikarpov I-16|I-16]] fighter in the service of the [[Republic of China Air Force|ROCAF]] in Nanjing]]
Following the [[Mukden Incident|Manchurian Incident of 1931]], the Chinese government began a fast track national defense program with massive construction of primary and auxiliary air force bases around the capital of Nanjing including [[Jurong Airfield|Jurong Airbase]], completed in 1934, from which to facilitate aerial defense as well as launching counter-strikes against enemy incursions; on August 15, 1937, the [[Imperial Japanese Navy Air Service|IJN]] launched the first of many heavy ''schnellbomber'' (fast bomber) raids against Jurong Airbase using the advanced [[Mitsubishi G3M|G3Ms]] based upon [[Giulio Douhet]]'s blitz-attack concept in an attempt to neutralize the Chinese Air Force fighters guarding the capital city, but was severely repulsed by the unexpected heavy resistance and performance of the Chinese fighter pilots stationed at Jurong, and suffering almost 50% loss rate.<ref>{{Cite news |date=October 5, 2020 |title=88年前，镇江有一座"句容飞机场"，它的前世今生很传奇……_手机网易网 |url=https://3g.163.com/news/article_cambrian/FO6AVPJJ0521PJRE.html}}</ref><ref>{{Cite web |title=Chinese Air Force vs. The Empire of Japan |url=https://www.warbirdforum.com/cafhist.htm |url-status=live |archive-url=https://web.archive.org/web/20071102114835/http://www.warbirdforum.com/cafhist.htm |archive-date=November 2, 2007 |access-date=October 31, 2020}}</ref>
[[File:Aerial_shot_of_Nanking_city_wall_1930.jpg|thumb|Nanjing's stone city walls as photographed in 1930]]
On November 20 the Chinese Army and teams of conscripted laborers began to hurriedly bolster Nanjing's defenses both inside and outside the city.<ref name="jiken22" /><ref>{{Cite journal |last=Tokushi Kasahara |year=1992 |script-title=ja:南京防衛戦と中国軍 |journal=南京大虐殺の研究 |language=ja |location=Tokyo |publisher=Banseisha |pages=250–251 |editor=Tomio Hora |display-editors=et al}}. This source cites secret telegrams sent by General Tang Shengzhi.</ref> Nanjing itself was surrounded by formidable stone walls stretching almost {{convert|50|km|mi|abbr=off|sp=us|spell=in}} around the entire city.<ref>Hallett Abend, "Japanese Reach Nanking," ''The New York Times'', December 7, 1937, 1, 13.</ref> The walls, which had been constructed hundreds of years earlier during the [[Ming Dynasty]], rose up to {{convert|20|m|ft|abbr=off|sp=us|spell=in}} in height, were {{convert|9|m|ft|abbr=off|sp=us|spell=in}} thick, and had been studded with machine gun emplacements.<ref>F. Tillman Durdin, "Invaders Checked by Many Defenses in Nanking's Walls," ''The New York Times'', December 12, 1937, 1, 48.</ref> By December 6 all the gates into the city had been closed and then barricaded with an additional layer of sandbags and concrete {{convert|6|m|ft|abbr=off|sp=us|spell=in}} thick.<ref name="laststand22">F. Tillman Durdin, "Chinese Fight Foe Outside Nanking," ''The New York Times'', December 8, 1937, 1, 5.</ref><ref name="integer22">{{Cite book |last=Noboru Kojima |publisher=Bungei Shunju |year=1984 |location=Tokyo |pages=165–167 |language=ja |script-title=ja:日中戦争(3)}}; Kojima relied heavily on field diaries for his research.</ref>

Outside the walls a series of semicircular defense lines were constructed in the path of the Japanese advance, most notably an outer one about {{convert|16|km|mi|abbr=off|sp=us|spell=in}} from the city and an inner one directly outside the city known as the Fukuo Line, or multiple positions line.<ref name="dorn22">Frank Dorn, ''The Sino-Japanese War, 1937–41: From Marco Polo Bridge to Pearl Harbor'' (New York: Macmillan, 1974), 88–90.</ref><ref name="garrison22">David Askew, "Defending Nanking: An Examination of the Capital Garrison Forces," ''Sino-Japanese Studies'', April 15, 2003, 153–154. Here Askew cites American military officer Frank Dorn, journalist F. Tillman Durdin, and the research of the Japanese veterans' association Kaikosha.</ref><ref>"Nanking Prepares to Resist Attack," ''The New York Times'', December 1, 1937, 4.</ref> The Fukuo Line, a sprawling network of trenches, moats, barbed wire, mine fields, gun emplacements, and pillboxes, was to be the final defense line outside Nanjing's city walls. There were also two key high points of land on the Fukuo Line, the peaks of Zijinshan to the northeast and the plateau of Yuhuatai to the south, where fortification was especially dense.<ref name="jiken22" /><ref>{{Cite book |last=Noboru Kojima |publisher=Bungei Shunju |year=1984 |location=Tokyo |page=175 |language=ja |script-title=ja:日中戦争(3)}}; Kojima relied heavily on field diaries for his research.</ref><ref name="zijinshan22">{{Cite book |last=Yoshiaki Itakura |publisher=Nihon Tosho Kankokai |year=1999 |location=Tokyo |pages=77–78 |language=ja |script-title=ja:本当はこうだった南京事件}}</ref> In order to deny the Japanese invaders any shelter or supplies in this area, Tang adopted a strategy of [[scorched earth]] on December 7, ordering all homes and structures in the path of the Japanese within one to {{convert|2|km|mi|abbr=off|sp=us|spell=in}} of the city to be incinerated, as well as all homes and structures near roadways within {{convert|16|km|mi|abbr=off|sp=us|spell=in}} of the city.<ref name="jiken22" />