The United States is sending a third aircraft carrier strike group to the waters around Iran, an American official told Al Jazeera, as the war there enters its eighth month and Washington and Tehran weigh escalation against diplomacy.
The official said the USS Theodore Roosevelt left its base in San Diego on Sunday, followed a day later by the Makin Island Marine Expeditionary Force, which carries more than 2,000 Marines. The deployment adds to a buildup that already includes some 50,000 American troops and F-35 fighter jets. By late November, Al Jazeera reported, three carriers and two amphibious landing groups are expected to be stationed near Iran.
The reinforcement comes a month before the United States holds midterm elections in which President Trump’s Republican Party could be punished for his handling of the war, which polling cited by Al Jazeera shows is deeply unpopular at home.
Across the Atlantic, the conflict arrived in Britain on Thursday. Counterterrorism police arrested a dual British-Iranian national in central London on suspicion of preparing terrorist acts, the sixth arrest in an investigation into a security incident at R.A.F. Fairford, an air base in southwest England that American bombers have used to strike Iran. The police said the man was 25; an earlier Al Jazeera report on the arrest put his age at 27.
Officers searched two properties in the capital, Counter Terrorism Policing said in a statement. A second man, 26, a British national, was questioned under caution.
The case began in the early hours of Sunday, when five men, all British nationals in their 20s from London, were arrested near the base in Gloucestershire, about 100 miles west of London, on suspicion of explosives and terrorism offenses. Armed officers and army bomb-disposal specialists moved in, and scores of residents were evacuated. The police later said they had found a quantity of petrol in three vans linked to the suspects but no explosives. The five were released on bail on Monday.
“The investigation into circumstances surrounding events in Gloucestershire is hugely complex, and our specialist teams are interrogating multiple lines of inquiry,” Vicki Evans, the senior national coordinator for Counter Terrorism Policing, said in a statement. “As we’ve made clear, we’re looking at all possible angles, including possible foreign state involvement.”
Prime Minister Andy Burnham of Britain has said the government sees “strong indications” that Iran played a part in the incident, though he gave no details of what the suspects were planning or why London places blame on Tehran. Iran’s embassy in London called attempts to tie the country to the men arrested near the base “fabricated speculations” that fuel what it called “Iranophobia propaganda,” and Iran’s foreign minister, Abbas Araghchi, said the British authorities were “barking up the wrong tree.”
No evidence linking Iran to the incident has been made public, and the police have brought no charges. Al Jazeera’s Rory Challands, reporting from London, said the nature of the threat had still not been officially explained.
The base is not incidental. Since March, the United States has flown bombers from R.A.F. Fairford against Iranian missile sites that were targeting ships in the Strait of Hormuz, with British authorization. In July, Iran’s Islamic Revolutionary Guard Corps warned that bases used to launch attacks on Iran could be treated as legitimate targets.
The decision to free the five suspects on bail drew open criticism from Washington. Mr. Rubio, the secretary of state, said many people were “disturbed” by it. Mr. Trump, asked about it on Thursday as he left the White House for Texas, said: “I was surprised they were released on bail. I have a lot of respect, however, for Scotland Yard. I think they know what they’re doing. But I was a little bit surprised.”
Mr. Burnham countered that the authorities hold the investigation under “the strongest grip and the closest control,” and said British officials had spent the week explaining to their American counterparts “what is happening here, how things are being done.”
British officials have warned for months about the threat from hostile states acting through proxies. They say national security cases involving such activity, including by Iran, rose 50 percent in the six months through December 2025, and they attribute a string of arsons and other attacks, many aimed at Jewish communities, to proxies linked to Tehran. The dual national arrested on Thursday remained in custody; he has not been charged.