US-Israel Strike on Iran: Timeline of Escalating Conflict & Casualties (2026)

The Middle East is experiencing a dramatic escalation of conflict following a joint military operation launched by the United States and Israel against Iran on Saturday, February 28, 2026. The strikes, described as preemptive by Israel’s Defense Minister Israel Katz, have triggered a cascade of retaliatory attacks, resulting in mounting casualties and widespread disruption across the region. This timeline details the unfolding events, from the initial explosions in Tehran to the reported strikes on U.S. Military bases and the tragic loss of life, including the confirmed death of Iran’s Supreme Leader, Ayatollah Ali Khamenei.

Initial Strikes and Retaliation

The first reports of explosions in Tehran surfaced around 0620 GMT on February 28th, as reported by Xinhua News Agency reporters on the ground. Shortly after, Israel confirmed a “preemptive” strike, simultaneously declaring a nationwide state of emergency and activating air raid sirens. Iranian state media, Fars News Agency, detailed missile strikes in multiple cities, including the capital, Isfahan, Qom, and Kermanshah, with reports indicating a strike near Khamenei’s office. These initial actions were quickly identified by Israeli media as a joint U.S.-Israeli operation.

Within hours, both Israel and Iran closed their airspace, and assessments from both countries indicated a breakdown in the possibility of negotiations. Washington stated the strikes aimed to dismantle Iran’s security apparatus, while President Donald Trump announced a “large-scale military campaign” targeting Iran’s missile industry, naval forces, and nuclear capabilities. An Israeli source indicated the first phase of the operation was expected to last four days, focusing on senior leadership, including Khamenei.

Tehran responded swiftly, with Iranian media reporting preparations for “crushing” retaliation. Missile launches from Iran were detected, and explosions were reported in northern Israel, prompting civilians to seek shelter. Further explosions were reported in Tehran around 0900 GMT, as the Islamic Revolution Guard Corps (IRGC) announced large-scale missile and drone attacks. A senior Iranian official stated that retaliation would have “no red lines.”

Regional Spillover and Mounting Casualties

The conflict rapidly expanded beyond Iran and Israel, with reports of strikes targeting U.S. Military bases across the region. Explosions were reported in Bahrain, the United Arab Emirates, Qatar, Saudi Arabia, Kuwait, and Jordan. Iran appealed to the United Nations to intervene, describing the U.S.-Israeli actions as aggression.

Tragically, reports emerged of a deadly strike on a girls’ elementary school in southern Iran, with the death toll reaching 165 by Sunday, according to Iran’s official IRNA news agency. This incident underscores the devastating human cost of the escalating conflict. The IRGC claimed to have destroyed a U.S. Radar installation in Qatar, while the Israeli military asserted it had carried out large-scale strikes on Iran’s air defense systems, significantly degrading their capabilities.

Leadership Changes and Further Escalation

The situation took a dramatic turn on March 1st with the confirmation of Ayatollah Ali Khamenei’s death. Earlier reports from Iranian media indicated four of his relatives had also been killed. Trump confirmed Khamenei’s death on social media, stating that military operations would continue. CBS News, citing U.S. Officials, reported that approximately 40 Iranian officials, including Defense Minister Aziz Nasirzadeh and IRGC commander Mohammad Pakpour, had been killed. CNN’s live coverage details the rapid succession of these events.

In the wake of Khamenei’s death, Ali Larijani, secretary of Iran’s Supreme National Security Council, announced the formation of an interim leadership council to select a new supreme leader. The IRGC claimed to have launched four ballistic missiles at the U.S. Aircraft carrier USS Abraham Lincoln, marking a “new phase” in their retaliatory strikes. The Pentagon confirmed the deaths of three U.S. Troops, the first American casualties of the conflict. Further escalating tensions, the IRGC claimed to have struck three oil tankers belonging to the United States and Britain in the Gulf and the Strait of Hormuz, reporting the vessels were on fire.

The Broader Context: Iran-Israel Conflict

The current escalation is rooted in a long and complex history of conflict between Iran and Israel. As outlined by Wikipedia, the Iran-Israel conflict encompasses a proxy war, clashes during the Syrian civil war, and now, direct military strikes. The underlying tensions stem from Israel’s concerns over Iran’s nuclear program, its support for militant groups in the region, and its regional ambitions. Iran, in turn, views Israel as an occupying force and a key ally of the United States, which it considers its primary adversary. The recent strikes represent a significant departure from previous patterns of indirect confrontation, marking a dangerous escalation towards a full-scale war.

What’s Confirmed and What Remains Unclear

Several key facts are now confirmed: the joint U.S.-Israeli military operation against Iran, the initial strikes on Iranian infrastructure, the retaliatory attacks by Iran, the deaths of Ayatollah Ali Khamenei and multiple Iranian officials, and the first U.S. Casualties. However, significant uncertainties remain. The full extent of the damage inflicted on Iranian infrastructure is still being assessed. The precise objectives of the U.S.-Israeli operation beyond dismantling Iran’s security apparatus are unclear. The composition and intentions of the interim leadership council in Iran are also uncertain. The long-term consequences of the conflict for regional stability and global energy markets remain to be seen.

The Role of the United Nations and International Diplomacy

Iran has called upon the United Nations to respond to what it describes as U.S.-Israeli aggression. The UN Security Council held an emergency session on February 28th to discuss the conflict, but a unified response has been hampered by divisions among member states. The effectiveness of the UN in de-escalating the crisis will depend on its ability to secure a ceasefire and facilitate negotiations between the parties. However, given the deep-seated mistrust and animosity between Iran and Israel, the prospects for a diplomatic resolution appear bleak in the short term. Al Jazeera’s live updates provide ongoing coverage of the international response.

Contingency Planning and Leadership Transition

Mohammad Bagher Ghalibaf, Iran’s Parliament Speaker, stated that contingency plans were in place for the post-Khamenei period, suggesting a degree of preparation for a leadership transition. However, the process of selecting a new supreme leader is likely to be fraught with internal power struggles and political maneuvering. The outcome of this process will have significant implications for Iran’s domestic and foreign policies.

The current situation presents a complex and volatile landscape. The immediate priority is to prevent further escalation and protect civilian lives. However, the underlying tensions that fueled this conflict remain unresolved, and the risk of renewed hostilities remains high. The international community must operate urgently to de-escalate the crisis and create a pathway towards a sustainable peace.