Iranian officials have condemned Israel's killing of Hamas leader Ismail Haniyeh in Tehran, labeling it a 'costly strategic mistake' that may lead to severe repercussions. Ali Bagheri, Iran's acting foreign minister, emphasized that the action will bring grave costs to Israel and accused it of attempting to escalate conflict in the region. Following an emergency meeting of the Organization of Islamic Cooperation (OIC) in Jeddah, a declaration was issued holding Israel fully responsible for Haniyeh's death. Despite calls for restraint from the West, OIC members expressed support for Iran's right to retaliate. The ongoing conflict, which escalated after Hamas's October 7 attacks, has resulted in significant casualties on both sides, with fears of further escalation looming in the region.