Iran’s ferocious retaliation for US-Israeli strikes has rattled its neighbors

 Iran’s supreme leader, Ayatollah Ali Khamenei, was killed in an airstrike this week that also took out 49 other top Iranian officials, US President Donald Trump said. US Defense Secretary Pete Hegseth said Monday that Iran’s “nuclear pursuits” and the “swelling arsenal of ballistic missiles and killer drones” are “no longer tolerable.”

As the US military began massing military assets near Iran over the past few weeks, Tehran repeatedly warned that any US attack would not be met with the same “restraint” it showed during last summer’s 12-day war, which started when Israel launched a surprise attack on Iran that eventually drew in the United States.

Still, the response to Khamenei’s killing has triggered a response that few observers expected. The regime has fired more than 400 ballistic missiles and almost 1,000 drones at Arab states along the Persian Gulf since Khamenei’s killing, according to regional governments.

Even more striking was the rapid escalation by the Islamic Revolutionary Guard Corps (IRGC). Tactics once considered a last resort were deployed within the first 72 hours. Urban centers, energy infrastructure, airports and hotels across the gulf’s Arab states were hit, shaking populations long used to their relatively security. In three days, Iran’s devastating blows crippled the gulf’s tourism industry, knocked some oil and gas facilities offline, targeted international airports and US bases, killed American soldiers, injured dozens of civilians and sowed widespread chaos that eventually caused the downing of three US fighter jets in friendly fire.

Iranian forces switched to a “mosaic defense” tactic, Iranian Foreign Minister Abbas Araghchi said, deploying cells of military units operating under a decentralized system to conduct clandestine drone and missile launches from across the large country. Experts say mobile launchers designed to look like civilian trucks can easily launch cheaply produced drones and short-range ballistic missiles. Although the Trump administration unleashed what Hegseth said was “the most lethal and precise air power campaign in history,” Iran has managed to continue wreaking havoc on its neighbors over three days. The escalating strikes have forced airspace closures, stranded tens of thousands of travelers, shifted schools to remote learning and kept fearful residents indoors to avoid falling debris.