China's trade with and investment in Central Asia has soared in the past 10 years. The region's abundant energy and mineral resources enticed China, with its insatiable appetite for fuel and raw materials, while Central Asia's strategic position offered Beijing alternative trade routes to reduce its reliance on its eastern coast. The area also has become a central component of Beijing's Belt and Road Initiative, a campaign to expand China's trade ties, and, by extension, its influence, around the world. Chinese President Xi Jinping signed hefty infrastructure agreements with the leaders of Kazakhstan, Kyrgyzstan and Uzbekistan during the Belt and Road Forum on May 14-15. Three weeks later, he traveled to Kazakhstan -- his fifth state visit to Central Asia since unveiling the Belt and Road Initiative in 2013 -- for a meeting of the Shanghai Cooperation Organization. Though China is now Central Asia's biggest investor and trade partner, it...