Iran is threatening to send forces into neighbouring countries if the US strikes it again after the 3 November midterm elections, according to people briefed on Tehran's warnings.
Iranian officials have hinted that their forces could move into neighbouring states if the conflict widens, but have not said which ones. Privately, Tehran has warned Arab officials that new fighting could bring strikes on Saudi Arabia's oil sites and on strategic infrastructure in the Gulf.
On Sunday, Mohsen Rezaei, an Iranian national security official, threatened strikes on the United Arab Emirates, and on data centres and internet cables in the region. Iranian representatives have told mediators they could step up attacks on US forces, including attempts to sink American warships in the Middle East and kill their crews. In September, Iranian missiles passed close to US warships.
The people briefed say Iran has limited means to defend itself against modern US aircraft and cruise missiles. For that reason, threats of regional escalation are at the centre of its deterrence strategy.
There is now a relative lull in direct fighting between the two sides. Iran is using it to rebuild its missile and drone production and to strengthen defences at sensitive sites. Satellite images analysed by the Institute for Science and International Security show new earth mounds around the Pickaxe Mountain and Natanz nuclear sites.
President Donald Trump has ruled out strikes before the election, but he has spoken publicly about hitting Pickaxe Mountain. A third US carrier strike group and another Marine expeditionary unit are heading to the region, and the Pentagon is considering sending more air defence systems and munitions. Last week he pulled about 12 B-1 bombers from a military base in Britain because he fears the Islamic Revolutionary Guard Corps is preparing a drone attack.
Over the weekend, at least 3 merchant ships were hit in and around the Strait of Hormuz, the British maritime trade operations service said. A tanker from the United Arab Emirates caught fire in a drone attack off Oman, and two Indian sailors are missing. The Emirates had largely avoided attacks since late spring.
On Saturday, a Houthi missile hit Riyadh's international airport. At least 13 people were killed and hundreds were wounded.
State media in Iran are showing more and more pro-government rallies, and billboards in Tehran advertise training for civilians in the use of portable anti-aircraft missiles and sniper rifles. The Revolutionary Guard is promoting training for female commandos. In Tehran, a campaign called "Sacrificing Life" is under way, in which supporters of the regime sign up to die for the Islamic Republic.
Revolutionary Guard members visited a kindergarten in Sabzevar and showed a Tomahawk missile that they said was American and had been disarmed.