The assassination of Hamas leader Ismail Haniyeh in Tehran, reportedly by Israel, has escalated tensions across the Middle East and raised fears of a broader conflict. U.S. Secretary of State Antony Blinken has called for all parties to refrain from actions that could exacerbate the situation, emphasizing the need for a cease-fire between Israel and Hamas. In response, Iran's Supreme Leader Ayatollah Khamenei has vowed to avenge Haniyeh's death, and Iranian officials are convening with representatives from Lebanon, Iraq, and Yemen to discuss potential retaliatory actions. Protests have erupted in Istanbul, and Iranian officials have accused the U.S. of complicity in the assassination. Meanwhile, the United Nations Security Council has convened to address the escalating tensions, with calls for accountability directed at both Israel and Iran. The assassination complicates ongoing efforts for a cease-fire in the Gaza conflict and the release of hostages, stalling negotiations that had been underway.