Located north of Tibet and west of Mongolia, Xinjiang is one of the most isolated regions in the world. At 1,500 miles from the national capital of Beijing, officials in Xinjiang’s capital of Urumqi have responsibility for administering a vast, distant land that includes within its boundaries massive mountain ranges and thousands of miles of rocky, dry deserts. Called “Chinese Turkestan” by such famous explorers as Sir Aurel Stein and Sven Hedin, it is today known as the Xinjiang-Uighur Autonomous Region and covers one-sixth of China’s total territory, making it the largest administrative unit in China. In the northwest are the Tarbagatai Mountains, which form part of the northern Xinjiang-Soviet border. Under the influence of Sheng Shicai, Xinjiang had contributed to the USSR war effort. Disruption of such supplies doubtless refocused Soviet interest in this border region, whose residents had intermittently raised the flag of rebellion against their Chinese rulers.