U.S. President Donald Trump shakes hands with Chinese leader Xi Jinping on the sidelines of the Asia-Pacific Economic Cooperation summit in Busan, South Korea, on Oct. 30. | REUTERS Donald Trump and Xi Jinping are headed toward a summit next month with a shared desire to stabilize ties. That calm is being tested as both leaders rush to shore up strategic vulnerabilities over Iranian oil and AI. The Trump administration has ramped up scrutiny of Beijing’s ties with Tehran in the past week, sanctioning one of China’s largest private refiners. Treasury Secretary Scott Bessent has warned Chinese banks could face secondary sanctions if China keeps propping up the clerical regime’s revenues, with his department on Tuesday again urging financial institutions to steer clear of Iranian activities. Adding to the tensions, Beijing on Monday blocked Meta Platforms’ $2 billion bid for AI startup Manus — its most dramatic move yet to keep cutting-edge technology inside its borders.…