The 10th day of the war began with a development that may shape the trajectory of the conflict more than any exchange on the battlefield. Early on Monday, Iran’s Assembly of Experts selected Ayatollah Mojtaba Khamenei as the country’s new supreme leader. The transition that happened without any disruption signalled both institutional continuity and a consolidation of authority at a time when Iran remains under sustained military pressure. Within Iran, the appointment was immediately endorsed by the revolutionary core and the political and military elite that publicly pledged allegiance, while state media framed the succession as a stabilising step that ensured the continuity of the political system despite the wartime environment, and there were no signs of unrest in cities, suggesting public acceptance as well. The acceptance of the new supreme leader extended beyond Iran’s borders as well, particularly among actors aligned with Tehran’s regional network of allies in Lebanon, Iraq and Yemen who moved quickly...