For much of its 16 years of existence, the Shanghai Cooperation Organization, or SCO, has carried perhaps the greatest promise of any multilateral organization in Eurasia. Made up of Russia, China and four of the five Central Asian states—Turkmenistan, characteristically, kept the organization at arm’s-length—the SCO hasn’t just provided a high-level forum for discussing regional counterterrorism efforts. It has offered an outlet for Moscow and Beijing to coordinate their security and, increasingly, economic policies without concerns of Western input. The SCO was never quite a “counterweight to NATO” as some asserted, but it provided the groundwork for cohesion to come. […]