US-Iran fighting has flared up again around the Strait of Hormuz, a bad sign for oil markets and anyone hoping the recent peace talks would hold.

• Iran and the US read their new agreement differently: Iran says all ships must check in with it to pass through the strait, while the US and Gulf states say ships can use a southern route through Omani waters without asking Iran.
• Iran fears the southern route is a trick to strip away its power to close the strait if war restarts, so it fired warning shots at ships, and the US hit back — twice in about two weeks.
• The strait is Iran's biggest bargaining chip and its backup plan, which is why it guards control of it so fiercely.
• JD Vance suggested the US is using the truce mainly to refill oil supplies before any renewed fighting, feeding suspicion the US never wanted real peace.
• US intelligence still says Iran has not decided to build a nuclear weapon, and there's no fast, clean military option, which is likely why Trump hasn't launched a bigger strike.

Outlook: A compromise where ships notify both Iran and the Gulf states is possible, but for now the shooting is ongoing and the risk of wider war remains.