【明報專訊】At the G20 summit in Bali, Indonesia, Chinese President Xi Jinping had a face-to-face meeting with US president Joe Biden, which has become an international focus. Over the past few years, there has been a downward spiral in Sino-US relations. This "Xi-Biden summit" could be seen as a reset of the relationship between the two countries. The two reiterated their respective principles and bottom lines and agreed to maintain strategic communication and contact in areas such as diplomacy, security, economy and trade and climate change. This is of positive significance for the prevention of conflict by drawing a red line. However, Biden's remarks about the "vigorous competition" between the US and China highlight that Washington will not ease up on its suppression of China's technology and economy and trade. US politicians eyeing the 2024 general elections have been inexhaustible in playing the anti-China card. If they do not know how to exercise restraint and cross Beijing's red line, all the previous efforts made to avoid conflict between the two countries may go down the drain.