History of the Great Wall of China the three, China's chief concern since the earliest times had been Mongolia – the home of many of the country's fiercest enemies including the Xiongnu, the Xianbei, the Khitans, and the Mongols. The Gobi Desert, which accounts for two-thirds of Mongolia's area, divided the main northern and southern grazing lands and pushed the pastoral nomads to the fringes of the steppe. On the southern side (Inner Mongolia), this pressure brought the nomads into contact with China. For the most part, barring intermittent passes and valleys (the major one being the corridor through Zhangjiakou and the Juyong Pass), the North China
The Battle of China and less often as "Nips"—blockading and occupation of China's ports is discussed and the rebuilding of China's destroyed rail system called the work of "slave labor". "New China"—here used to reference the Republican government-in-exile in Chongqing—is shown as connected to the outside world only through the "narrow-gauge" Indo-Chinese railway and the "camel caravans" from Russia across the Gobi Desert. (The railway is described as "limited" and "too near Jap territory to be safe", with French compliance in closing the line for Japan omitted.) The construction of the Burma Road between Lashio in Burma and the truck road to Kunming is