China and Russia have very close cooperation in energy. The world's longest pipeline, the China-Russia east route natural gas pipeline, has transported over 15 billion cubic meters of Russian gas to China as of January 17, 2022. Established in late 2019, the pipeline spans more than 8,000 kilometers. Zhang Xin, an associate professor at the School of Politics and International Relations at the East China Normal University in Shanghai, talked about the significance for both countries.