Why is it said that advancing into Dabie Mountain is the beginning of China People's Liberation Army's strategic offensive?

Dabie Mountain is located at the junction of Hubei, Henan and Anhui provinces between Nanjing, the capital of the Kuomintang, and Wuhan, an important town in the middle reaches of the Yangtze River. It is the most sensitive and weak area in the enemy's strategy. It is an old revolutionary base, with no resources and a good mass base. The PLA is easy to take root. Occupy Dabie Mountain, you can scare Nanjing in the east, Wuhan in the west, Changsha in the south and have a bird's eye view of the Central Plains. Mao Zedong proposed to leap into the Dabie Mountains, determined not to be in the rear, and went straight into the enemy's strategic depth. First, occupy the vast rural areas, establish revolutionary base areas, surround cities with villages, and then seize cities.

At that time, the strategic intention of the CMC was to leap into Dabie Mountain with Liu Dengjun; The main force of Taiyue Corps led by Chen Geng and Xie Fuzhi is the Right Rear Army. Hu Zongnan was trapped in northern Shaanxi, and when the enemy of western Henan was at a disadvantage, he crossed the Yellow River from southern Shanxi, advanced into western Henan with thunderous momentum, and relied on Funiu Mountain to fight to create the base area of Henan, Shaanxi and Hubei. The main force of the East China Field Army led by Chen Yi and Su Yu was the left rear army, which advanced into the Sulu, Henan and Anhui regions. The containment of the two wings is: Peng led the northern Shaanxi field army to attack Yulin area, and mobilized the Hu Zongnan regiment that attacked northern Shaanxi to the north; Shandong People's Liberation Army launched an offensive in Jiaodong, leading the Kuomintang troops attacking Shandong to advance to the seaside. The Central Committee has repeatedly asked the two wings to cooperate with the middle and the three armed forces to ensure the main force. Zhou Enlai once said, "Liu Deng went straight to Dabie Mountain and stabbed Chiang Kai-shek in the chest! Chen Geng and Xie Fuzhi Corps crossed the Yellow River in the south, advanced into western Henan, and then beheaded him! Chen Yi and Su Yu's army entered the southwest of Shandong, advanced into the west of Henan, and stabbed him again! Strategically, these three armies have formed a "pin" battle array, which is a horn of each other and cooperates with each other. From the Yangtze River in the south, the Yellow River in the north, the Hanshui River in the west, and the Yellow Sea in the east, they launched a large-scale attack on the enemies in the Central Plains. " Liu Deng's army and Xie Chen and Chen Su, who later advanced into western Henan, Anhui and Jiangsu, formed a zigzag formation. They are the horns of each other, pushing forward the Kuomintang's Yangtze River defense line with their feet, making the vast Central Plains a forward base for all-round victory.