Poised to become the king of pipelines, with a total route of more than 2,600 kilometers (1,615 miles), Power of Siberia-2 is set to change two things forever: global natural gas flows and the already solid alliance between China and Russia. A few loose ends remain before it becomes reality, but after Tuesday’s meeting between Xi Jinping and Vladimir Putin, the road appears paved for the pipeline that will link the Yamal Peninsula ― one of the w…