Just hours before Donald Trump arrived in China for a high-stakes summit with President Xi Jinping, Beijing issued a dramatic warning to Washington by unveiling four major “red lines” the U.S. must not cross. The Chinese Embassy in the U.S. identified Taiwan, democracy and human rights, political systems, and China’s development rights as core issues tied directly to Beijing’s sovereignty and national security. The warning comes as tensions rise over the Iran war, trade disputes, sanctions, Taiwan, and growing military rivalry between the world’s two biggest powers. Trump said he plans to discuss Iran, oil, and trade with Xi during the visit, while Beijing accused Washington of targeting Chinese companies over alleged ties to Tehran.