Among the five Central Asian states, Kazakhstan stands out. Vast energy resources and a strategic location have lent the sprawling country considerable geopolitical importance and drawn the eye of outside powers. Since the state gained independence in 1991, Russia has kept the close ties it forged with Kazakhstan during its imperial and Soviet periods. China has taken a growing interest in the country, too, importing Kazakh energy and planning deeper inroads into its northwestern neighbor through the Belt and Road Initiative . And even the United States has a stake in the former Soviet republic, both because of its energy industry — California-based Chevron Corp. is a key partner in multiple major Kazakh energy projects — and because of its proximity to Afghanistan.