The spat between Iran and Pakistan earlier this year—a clash which saw armed cross-border operations by both sides—raises questions about China's potential role as a regional peace broker. Despite attempts to get involved, Beijing remained largely on the sidelines as Islamabad and Tehran de-escalated the situation on their own. This was surprising to many who had anticipated that China might emerge as the region’s next diplomatic heavyweight following its hosting of successful Iranian-Saudi normalization talks in Mar. 2023. As tensions brew in the Red Sea, Beijing’s credibility as a mediator has once again been put to the test.

Reports say that China unsuccessfully tried to cajole Iran into pushing the Ansarullah movement, better known as the Houthis, to rein in their attacks on commercial vessels—a claim that Tehran denies. Whether or not this is...