US intelligence warns Iran may retaliate against America over Khamenei’s killing

US warns of persistent Iran threat

Iran and its allied proxy groups could seek to retaliate against the United States following the 28 February killing of Iran’s Supreme Leader, Ayatollah Ali Khamenei, in joint US–Israeli strikes, according to a US intelligence assessment reviewed by Reuters.

The assessment, prepared by the Department of Homeland Security’s Office of Intelligence and Analysis, indicates that while a major physical assault on American soil is considered unlikely, the threat environment remains active and evolving.

It stated that “a large-scale physical attack is unlikely, [but] Iran and its proxies probably pose a persistent threat of targeted attacks in the Homeland.”

Officials warned that potential retaliation may take the form of targeted operations or cyber activity. The report highlighted the risk posed by Iran-aligned “hacktivists”, who could carry out website defacements or distributed denial-of-service attacks against US networks in the near term.

Homeland Security Secretary Kristi Noem told Reuters, “I am in direct coordination with our federal intelligence and law enforcement partners as we continue to closely monitor and thwart any potential threats to the homeland.”

Beyond domestic risks, the assessment cautioned that Tehran is likely to continue striking US and allied interests across the Middle East. It also noted the possibility that senior American officials could be singled out if unrest breaks out in response to President Donald Trump’s calls for regime change in Iran.

Although intelligence officials currently assess the immediate danger of a mass-casualty attack within the United States as low, the document stresses that Iran and its proxies represent a “persistent threat” that could shift as the conflict develops.

The warning comes amid intensifying US–Israeli military operations against Iran. In a post on Truth Social, President Donald Trump declared that Iran’s “air defense, Air Force, Navy, and Leadership is gone,” adding, “They want to talk. I said ‘Too Late!’”

The post was published as strikes continued and included a link to an opinion article by Marc Thiessen in The Washington Post defending Trump’s decision to authorise military action.

With tensions running high, US authorities say they remain alert to both physical and digital risks, even as the broader confrontation shows little sign of easing.