The U.S. Department of State issued [1] a Worldwide Caution Security Alert on Sunday, urging American citizens overseas to exercise increased vigilance following U.S. airstrikes on Iranian nuclear facilities over the weekend.
The advisory comes amid rising tensions in the Middle East, as the conflict between Israel and Iran escalates.
“The conflict between Israel and Iran has resulted in disruptions to travel and periodic closure of airspace across the Middle East,” the alert stated.
“There is the potential for demonstrations against U.S. citizens and interests abroad. The Department of State advises U.S. citizens worldwide to exercise increased caution.”
The department also recommended that travelers review detailed country-specific guidance available through the State Department’s official travel website before making any international plans.
Worldwide Caution: The conflict between Israel and Iran has resulted in disruptions to travel and periodic closure of airspace across the Middle East. There is the potential for demonstrations against U.S. citizens and interests abroad. The Department of State advises U.S.… pic.twitter.com/PXJCvSHNxy [2]
— Travel – State Dept (@TravelGov) June 22, 2025 [3]
The alert followed a U.S.-led military operation Saturday night targeting key Iranian nuclear sites, including Fordow, Natanz, and Esfahan. The strike, which deployed GBU-57 “bunker buster” bombs, was carried out in coordination with Israel as part of ongoing efforts to deter Iran’s nuclear weapons development.
In addition to the global alert, the Department of Homeland Security issued a separate National Terrorism Advisory System Bulletin highlighting a heightened domestic threat environment within the United States.
“The ongoing Iran conflict is causing a heightened threat environment in the United States,” the bulletin stated.
“Low-level cyber attacks against U.S. networks by pro-Iranian hacktivists are likely, and cyber actors affiliated with the Iranian government may conduct attacks against U.S. networks.”
The bulletin also referenced longstanding threats by Iran against U.S. officials believed to be connected to the January 2020 death of Iranian Quds Force commander Qassem Soleimani.
Intelligence assessments warn that Iran maintains an operational interest in pursuing retribution.
“The likelihood of violent extremists in the Homeland independently mobilizing 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 advisory continued.
Officials also noted that recent domestic terror incidents have been tied to anti-Semitic and anti-Israel motivations, and warned that the ongoing Israel-Iran conflict could further motivate U.S.-based individuals to conduct additional attacks.
U.S. Customs and Border Protection (CBP) Commissioner Rodney Scott and Border Czar Tom Homan also raised concerns related to potential infiltration by foreign nationals amid ongoing immigration challenges at the southern border.
Both officials referenced the increased threat of sleeper cells, pointing to Iranian nationals who may have entered the U.S. under the Biden-Harris administration’s border policies.
“Open border policies have created vulnerabilities that hostile foreign actors may exploit,” said Homan, who has long advocated for enhanced border security and intelligence vetting procedures.
JUST IN: Tom Homan warns of Iranian sleeper cells in the U.S.
“Joe Biden let MILLIONS of unknown gotaways cross the border. We don’t know who they are… but Iranian passports were found ditched south of the border with prayer mats.”
“What gives me comfort is that we don’t… pic.twitter.com/ikohH5FgLm [4]
— Nick Sortor (@nicksortor) June 22, 2025 [5]
Commissioner Scott added that border enforcement personnel have reported encounters with individuals of interest from multiple regions, including the Middle East, in recent months.
The combination of overseas instability, domestic threats, and continued border concerns has prompted a coordinated response from federal agencies tasked with national security and emergency preparedness.
U.S. officials have stated that they are monitoring the situation closely and are prepared to take additional steps to secure American personnel, facilities, and interests at home and abroad.
Travelers and residents are urged to remain aware of their surroundings, stay informed through official government channels, and report any suspicious activity to the appropriate authorities.