As China and the U.S. hold in-depth trade talks in Madrid, World Trade Organization (WTO) Deputy Director-General Zhang Xiangchen tells CGTN's Tian Wei that constructive dialogue between the world's two largest economies is key to stabilizing global tensions. He stressed that smaller nations must not be overlooked, warning: "If elephants fight, the grass will suffer." Upholding the WTO's non-discrimination principle, he added, is essential to protecting vulnerable members and sustaining the multilateral system.