When talking about national defense fortifications, we must mention the 128th Shanghai War of Resistance in the 21st year of the Republic of China (1932).

Although the 19th Route Army fought bravely, China was at an absolute disadvantage in terms of army, navy and air force compared with Japan. After the Japanese army increased its troops three times and changed its commander four times, the 19th Route Army was still defeated. Zhang Zhizhong led the Fifth Army of the "Imperial Guard" to join, but failed to reverse the decline. Chairman Chiang was even ready to move the capital to Luoyang.

However, in the end, the United States, Britain, France, Germany and other Western powers were unwilling to have Japan and China occupy the rich middle and lower reaches of the Yangtze River, so they joined forces to put pressure on the Japanese government. At that time, the Western world did not form a tense confrontation between the two major war groups, so the joint pressure from the great powers was still very deterrent, and the Japanese government finally surrendered.

The 28th Incident ended with a ceasefire negotiation, but Chairman Chiang was still scared and sweated. Chiang felt deeply that there was a huge gap in national strength and military strength between China and Japan. If it weren't for the Western powers' intervention, it might have made the Japanese dynasty arrive in Luoyang. So Chairman Chiang made up his mind to change such an unfavorable situation.

It was also coincidental that Mr. Zhang was quite loyal to Chairman Jiang at that time, and local warlords such as Feng Yuxiang, Yan Xishan, Li Zongren were quite honest, and domestic politics were still calm. Chairman Jiang began to do his best to rectify the army. With the help of the German advisory group, he developed a five-year military reorganization plan and decided to reorganize 60 German armed divisions within five years!

The German-Armed Division on the paper had more than 17,000 soldiers, and had six infantry regiments, artillery, engineers, communications, spies, baggage, and cavalry battalions. However, until the Battle of Songhu broke out, only one German-Armed Division on the paper had been organized into one, which was the model unit. The Central Military Academy Teaching Corps, and three of them had only officer skeletons, and the soldiers were not filled.

In addition to reorganizing the army, Chairman Chiang also decided to build national defense fortifications in the Beijing, Shanghai and Hangzhou area, because Chairman Chiang knew very well that there was a huge gap in national strength between China and Japan. Even if they had planned to form 60 German divisions, China would definitely be on the defensive side in the future, so they also needed to use solid fortifications to last fortifications.

To preside over the construction of such a huge national defense fortification, a military strategist with outstanding reputation and outstanding capabilities must be prestigious.

At that time, there were only three and a half people recognized by the Chinese military or qualified to serve as the Chief of General Staff. Among them, Chiang Baili had the most reputation. Unfortunately, he had the experience of overthrowing Chiang. Chairman Jiang did not trust him, and Liu Bocheng had the strongest ability. Unfortunately, he had already joined the Communist Party. Bai Chongxi had a slightly inferior reputation and ability. Moreover, he was the second leader of the Guangxi clan. Chairman Jiang still did not trust him. Apart from these three people, there was only the last half of the military strategist, and he was Yang Jie.

However, Yang Jie was in a state of disagreement because he failed to compete for favor with He Yingqin. He didn't even do the minimum field survey. He spent two and a half days to draw a few lines on the drawings and compiled a "Beijing-Shanghai-Hangzhou Fortification Plan." The entire plan range was very large. The most bizarre thing was that he actually adopted a locked fortress defense plan for a city as big as Nanjing. In other words, he was going to build Nanjing into a super fortress, but his archenemy He Yingqin criticized him for being bloody, saying that he had no form and rigid thoughts.

Chairman Jiang also felt that Yang Jie was passive and did not give him face to Jiang, so he drove him to Europe for "inspection". Then Chairman Jiang began to ask the German advisory group, saying that the Germans were much more rigorous. They spent several months on-site inspections and finally proposed an extremely rigorous defense plan. According to this defense plan, with the military and firepower level of the Japanese army at that time, there was no hope of breaking through the defense line and attacking Nanjing. However, this plan also had a fatal disadvantage, that is, the cost was too high, and the National Government had to not eat or drink for several years to save money to build national defense fortifications.

In the end, Chairman Jiang had no choice but to hand over the task to the General Staff Department of the Military Commission. The senior leaders of the General Staff did not disappoint Chairman Jiang's expectations. After a lot of field investigations, they proposed a plan that has reasonable explanations and differences in the possible direction of the Japanese army's offensive and the focus of the entire defense plan.

The plan believes that the Japanese army is most likely to attack Nanjing from Shanghai along the Yangtze River, the Beijing-Shanghai Railway, so it advocates the construction of national defense fortifications in Fushan, Changshu to Wuxian, Jiangyin to Wuxi, and set up attack positions and rear assembly positions in front and back to form two national defense lines with battalion-level fortification communities as the main body, namely the Wufu Line and the Xicheng Line.

The plan also did not ignore the possibility of the Japanese landing from Hangzhou Bay. It advocated the construction of coastal fortresses in Zhapu, Zepu, Tuolin and other places, and the construction of national defense fortifications in Zhapu, Jiashan to Suzhou, Haiyan through Jiaxing to Wujiang, and also built offensive positions and assembly positions in the front and back, which are the Jiazha Line and the Haijia Line.

In addition to these four national defense lines, Fukuo positions and peripheral defense lines must be built in Nanjing. Fukuo positions are supported by city walls, and the peripheral defense lines start from Dasheng Pass, pass through Niushou Mountain, Fangshan, Chunhua Town, Tangshan Town to Qixia Mountain to form an arc-shaped fortification group. Behind them, relying on the Yangtze River Chamber, forming a complete defense circle.

Chairman Jiang adopted the plan and started construction in the 23rd year of the Republic of China. By the 25th year of the Republic of China, the main body of the project was Wu Fu, Xicheng, Jiazha and Haijia.

The four national defense lines are mainly composed of battalion-level fortification groups, and a small number of important areas are strengthened into regiment-level fortification groups. All heavy machine gun nests, artillery positions, observation centers, cover, and ammunition depots are all built with reinforced concrete waves into permanent fortifications. In wartime, only traffic trenches need to be dug, and scattered trenches can form complete fortifications.

The top wall of all permanent fortifications is more than one meter, which is enough to withstand the bombardment of 150mm caliber heavy artillery artillery and the bombardment of 500 pounds of aircraft bombs. The top of the underground cover is more than two meters, which is enough to withstand the bombardment of 1,000 pounds of aircraft bombs. During this period, due to corners and design errors, some mistakes are inevitable, but overall, they will not be much different.

Such four national defense lines, which were built with a lot of money, could have played a great role and greatly damaged the Japanese army. If ten to twenty divisions could be used to defend themselves on the national defense line, it would be difficult for the Japanese army to quickly cross the national defense line. However, due to the serious strategic mistakes of Chairman Chiang's growth, these four national defense lines had almost no effect.

The 19th Brigade encountered in Xu Jiabin by no means accidental. The 51st Division, which was fortified near Suzhou and the troops near Changshu, all encountered similar situations.

Because they did not know the specific location of the fortifications, the officers and soldiers of the National Army could only dig up soil bags everywhere, but they dug many grave bags. Even if they were dug up for the fortifications, they still couldn't enter the fortifications. There were a few townships. The chief of the army did not run away and gave the keys. As a result, the key hole had been embroidered for a long time and could not be opened because the key hole had not been maintained for a long time.

The large number of permanent fortifications built along the Wufu Line can be used in the end, and only a very small number of permanent fortifications that have been used have basically not played their due role, because even the strongest fortifications must be guarded, and the fighting spirit of these national troops who were defeated from the battlefield of Songhu have long disappeared.

Speaking of which, the fortifications on Wu Fu's line still played a little role. The most regrettable thing is that the two national defense lines, Jiazha and Haijia, were too sudden for the Japanese army to land in Jinshanwei, and the main forces of the national army had been transferred to western Shanghai at that time, so the Japanese army almost crossed these two national defense lines without bloodshed.

When the Japanese army on the southern front advanced rapidly around the southern bank of Taihu Lake and captured Yixing, the last and most solid national defense line, Xicheng Line, could not continue to stick to it. The only thing that is thankful is that the Sichuan army was in Guangde, Si'an blocked the Japanese army on the southern front, and the Jiangyin Fortress also locked the Yangtze River firmly, which won time for the retreat of the main force of the national army.

By late November, the main forces of the national army retreated from the Songhu battlefield basically retreated to Ji'an and Chuzhou.

At this time, Chairman Jiang had already made up his mind to defend Nanjing after convening three meetings of aides. The Nanjing Garrison Command, which had Tang Shengzhi as the commander-in-chief, was officially listed. However, the troops affiliated to the Garrison Command at that time were only 71st Army, 72nd Army and 78th Army except for the Gendarmerie Corps.

Although the 71st Army, 72nd Army and 78th Army are all in the army level, each army actually has only one division, namely the 87th Division, 88th Division and 36th Division. To put it bluntly, the Nanjing Garrison Command is actually the original Beijing-Shanghai Security Command, and it is far inferior to the Beijing-Shanghai Security Command, because the Beijing-Shanghai Security Command also includes four regiments, namely the Shanghai Security Corps, the Shanghai Police Corps and Jiangsu Security Corps, and they are all full units.

Of course, the troops could not defend Nanjing with such a small amount, so Chairman Jiang asked Tang Shengzhi, which other troops do you want?

Tang Shengzhi and Chairman Jiang have been fighting for the boss for decades. They are so treacherous and sloppy that they know Chairman Jiang's character well, so they ask Chairman Jiang: Are you taking it away if you have any Central Military Academy Teaching Corps?

Chairman Jiang trembled for a moment and gritted his teeth and said, "I'll give it to you!"

Tang Shengzhi asked again, would you still take Yu Jishi's 74th Army?

Chairman Jiang gritted his teeth and stomped his feet, saying, "The Seventy-Fourth Army will also leave you!" As a result, Chairman Jiang's most direct troops were all in Nanjing. He thought to himself that he could not let these troops fight all, and he had to leave them cannon fodder troops. So the Guangdong Army's 66th Army, 83rd Army and Xu Yuanquan's 2nd Army were also assigned to Tang Shengzhi.

Tang Shengzhi had foreseeed such a result, holding the most elite and most capable divisions at that time. Tang Shengzhi was still very confident about holding Nanjing for several months. In his opinion, in these few months, the Japanese army should have been exhausted from the veterans, and the national army could almost organize troops to counterattack.

If he could complete the Jedi counterattack in Nanjing, then he, Tang Shengzhi, would be worthy of being famous in history!
Chapter completed!