Iran's threatened retaliatory strike on Israel over the assassination of Hamas official Ismail Haniyeh drew major world powers on Tuesday into a high-wire act of diplomacy.

Halting or limiting an Iranian strike in some eyes could bolster a monthslong effort to reach a cease-fire in a war that's devastated the Gaza Strip and killed nearly 40,000 Palestinians, according to the territory's health ministry. It could also free the Israeli hostages who remain captive there since Hamas' Oct. 7 attack on southern Israel.