President Biden has said "all-out war" in the Middle East has to be avoided after Hezbollah leader Hassan Nasrallah was killed in Israeli airstrikes on Beirut.  The White House has tried to tread carefully to contain tensions between Israel and both Hamas and Hezbollah, who are backed by Iran.   But the strikes which killed Nasrallah happened hours after Israel's Prime Minister Benjamin Netanyahu spoke to the United Nations - raising questions about the effectiveness of diplomacy and what the international community can do to avoid escalation.  On this episode of the Sky News Daily, Niall Paterson is joined by military analyst Michael Clarke and Sky's international affairs editor Dominic Waghorn to ask what the world's biggest powers can do to prevent war in the region. Producer: Soila Apparicio  Editor: Paul Stanworth