中美伦敦谈判激烈博弈，美方首席代表提前离场，连夜赶回美国复命

Group 1 - The core negotiation framework between the US and China has been largely established, with key terms agreed upon, leading to the departure of US Treasury Secretary Bessent from the talks [2][7][10] - The US has shown a rare pragmatic attitude by considering the removal of recent restrictions on chips, ethane, and nuclear materials, which were previously used as leverage against China [4][10] - The transition of negotiation leadership from Bessent to Commerce Secretary Lutnick indicates a strategic shift in the US approach towards China, focusing more on export controls and technology transfer issues [12][14][27] Group 2 - Lutnick's involvement in the negotiations suggests a more aggressive stance on export controls, as he has publicly stated the need to include these issues in trade agreements [14][16] - The US is demanding that China fully open its rare earth exports in exchange for limited concessions on technology restrictions, reflecting a tactical approach to leverage China's strategic resources [16][29] - The internal political dynamics in the US, including speculation about Bessent's potential nomination as the next Federal Reserve Chair, may influence future negotiations and the overall economic strategy towards China [21][25][27]