The assassination of Hamas leader Ismail Haniyeh in Tehran has ignited a wave of outrage and vows of vengeance from Iran and Hezbollah, with Iranian officials accusing Israel of orchestrating the attack. Hezbollah leader Hassan Nasrallah condemned the killing as an infringement on Iran's sovereignty and declared a new phase in their conflict with Israel, warning of serious repercussions. The regional tensions have escalated in the wake of ongoing violence in Gaza, where over 40,000 have died, and recent Israeli strikes have intensified hostilities with Hezbollah. Iran's Supreme Leader, Ayatollah Khamenei, and President Masoud Pezeshkian emphasized a commitment to retaliate against perceived Israeli aggression. Meanwhile, Israeli Prime Minister Benjamin Netanyahu affirmed the country's military actions against Hamas and Hezbollah as necessary for national security. As mourners gather in Iran and Lebanon to honor the slain leaders, fears mount that retaliatory actions may further destabilize the region.