How to mediate between Iran and the United States when one side wants revenge for the killing of its leader and the other's erratic messaging seems ratings-driven? Donald Trump's unilateral ceasefire declaration has brought neither side back to the bargaining table, what with more ships seized in the Strait of Hormuz and lockdown mode relaxed in Pakistan's capital for talks that may or may not resume.

We ask about US demands that can change course inside the same presidential tweet, and an unclear chain of command on both sides: why was US Vice President JD Vance flanked by Trump confidantes Jared Kushner and Steve Witkoff last time? Does it actually matter that none of those three are trained diplomats or Iran specialists?

And who's really calling the shots in an Islamic Republic that's in survival mode? On that score, what are Tehran's intentions regarding Hezbollah? Its proxy militant group in Lebanon is absent as the US State Department in Washington brokers more old school-style negotiations between the Israelis and the Lebanese.

Who's got leverage over whom and if diplomacy fails, what does escalation look like?

Produced by François Picard, Rebecca Gnignati, Juliette Laffont, Ilayda Habip, Marguerite Lacroix, Andrew Hilliar.