US president Joe Biden with president Xi Jinping of China in Bali, Indonesia. Amid growing disputes over Taiwan, Ukraine, technology and divergent visions of the world order, the leaders of the two superpowers held their first face-to-face presidential talks. Photograph: Doug Mills/The New York Times After months of rising tensions between Washington and Beijing amid talk of economic decoupling and a new cold war, Joe Biden and Xi Jinping sought in Bali to turn down the heat. The disputes at the source of the tensions, including those over Taiwan, human rights, technological competition and fair trade, remain highly charged, but...