Agreement to end US-Iran war signed

A basic agreement has been signed to end the war between the US and Iran. The negotiations now turn to the really difficult issues: we hear from Iran and Israel. Also in the programme: Ukraine targets Moscow in a massive drone attack; researchers say it's way too easy to get around ChatGPT's guardrails; and an ancient oak tree in Sherwood Forest linked to Robin Hood has died - or is it just entering its next phase?