US-Iran preliminary peace deal reopens Strait of Hormuz and lifts naval blockade, but verification gaps and Israeli defiance leave energy market and sanctions certainty unresolved

A preliminary memorandum of understanding signed between the United States and Iran has resulted in the US lifting its naval blockade on Iranian ports and committing to reopen the Strait of Hormuz — the critical waterway through which a significant portion of the world's oil, gas, and fertiliser passes to global markets. The agreement creates a 60-day window, extendable by mutual agreement, for the two sides to negotiate a broader settlement. Despite the immediate de-escalation, the deal faces significant structural fragility. Vice President JD Vance delayed a planned trip to Switzerland to negotiate final terms, with the postponement raising questions about the agreement's durability. Iran has made clear that the deal requires Israel's withdrawal from southern Lebanon, a condition Israel has publicly rejected, with Prime Minister Benjamin Netanyahu stating Israeli troops will remain as long as Israel's security requires. For energy and commodities markets, the reopening of Hormuz is immediately significant — the strait is a chokepoint for roughly a fifth of global oil trade. However, the London Market Association (LMA) has separately noted that further clarification will be needed on the practical steps required to resume shipping, including the extent to which the US, UK, and EU will be lifting sanctions and designations with respect to Iran. This sanctions unwinding question has direct implications for marine insurers, commodities traders, and energy companies seeking to re-engage with Iranian counterparties.