Secretary of State Antony Blinken on Thursday issued a tough demand to “all parties” in the Gaza conflict to stop taking escalatory actions, a day after the assassination of Hamas political leader Ismail Haniyeh in Tehran. The attack — along with the killing of a senior Hezbollah official in Beirut — has heightened fears of a wider Middle East conflict, and is a major blow to cease-fire negotiations to end the war in Gaza. Thousands of people gathered in Tehran for Haniyeh’s funeral procession Thursday.