The Iranian supreme leader is backed into a corner, a situation he has spent his life doing his best to avoid

When he appeared in public for the first time in five years in October, Iran’s supreme leader, Ayatollah Ali Hosseini Khamenei, had an uncompromising message. Israel “won’t last long”, he told tens of thousands of supporters at a mosque in Tehran in a Friday sermon.

“We must stand up against the enemy while strengthening our unwavering faith,” the 84-year-old told the gathering.

Days before, Israel had killed Hassan Nasrallah, the veteran secretary general of Hezbollah, with huge bombs dropped on the militant Islamist movement’s headquarters in Beirut. The assassination was a personal blow to Khamenei, who had known Nasrallah for decades.

The Israeli air offensive against Iran, launched on Friday, is another such blow. It has prompted more defiance from Tehran, and a barrage of missiles and drones launched at Tel Aviv, but neither appear likely to stop the Israeli attacks. Iran’s air defences are apparently ineffective and the coalition of Islamist militias that Khamenei had built up to deter Israel is effectively shattered.