Advisory warns of ‘heightened threat environment’ in US after Iran strikes

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FILE PHOTO: A \"No war on Iran\" banner is held as people attend an anti-war demonstration in Los Angeles, California, U.S., June 21, 2025. REUTERS/David Swanson/File Photo

Protesters held a "No war on Iran" banner at an anti-war demonstration in Los Angeles, California, on June 21.

PHOTO: REUTERS

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NEW YORK – An advisory from the US Department of Homeland Security warned on June 22 of a “heightened threat environment in the United States” following overnight US military strikes on Iran’s nuclear sites.

Rights advocates have already noted heightened Islamophobia and antisemitism in the US since the start of US ally Israel’s war in Gaza following an October 2023 attack by Palestinian militant group Hamas.

The DHS issued June 22’s bulletin through its National Terrorism Advisory System and said the ongoing Iran conflict was causing the heightened threat environment.

Low-level cyber attacks against US networks by "pro-Iranian hacktivists" are likely, the bulletin said, adding cyber actors affiliated with Iran's government may also conduct cyber attacks.

"The likelihood of violent extremists in the Homeland independently mobilising to violence in response to the conflict would likely increase if Iranian leadership issued a religious ruling calling for retaliatory violence against targets in the Homeland," the bulletin said.

US President Donald Trump said late on June 21 he

“obliterated” Iran’s main nuclear sites

with massive bunker-busting bombs, joining Israel’s assault against its Middle East rival. The Israel-Iran war began with Israel’s attacks on Iran on June 13.

Local US authorities said late on June 21 they remained vigilant, adding there were no known credible threats. In Los Angeles, Washington and New York City, law enforcement agencies said they stepped up patrols and deployed additional resources to religious, cultural and diplomatic sites.

The Israel-Iran war could contribute to US-based individuals plotting additional attacks, the bulletin said, noting earlier attacks that it called antisemitic and anti-Israeli.

Recent US incidents that have raised alarm over antisemitism and anti-Israel attitudes include the fatal Washington shooting of two Israeli embassy employees and a Colorado attack that wounded eight people when a suspect threw incendiary devices into a pro-Israeli crowd.

Incidents that increased concerns about anti-Muslim prejudice include the fatal stabbing of a 6-year-old Palestinian child in Illinois, the attempted drowning of a 3-year-old Palestinian American girl in Texas and a violent mob attack on pro-Palestinian protesters in California. REUTERS

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