A woman holds a poster depicting Iran’s new supreme leader, Mojtaba Khamenei, during an anti-U.S. and anti-Israel rally in Tehran on March 26. | WEST ASIA NEWS AGENCY / VIA REUTERS

Dubai – Two months into a war with the U.S. and Israel, Iran no longer has a single, undisputed clerical arbiter at the pinnacle of power — an abrupt break with the past that may be hardening Tehran’s stance as it weighs renewed talks with Washington.

Since its creation in 1979, the Islamic Republic has revolved around a supreme leader with final authority on all key matters of state.…