From fortifying nuclear facilities to rebuilding structures to conducting naval exercises in the Persian Gulf, Iran appears to be taking steps to signal its readiness for war as the US continues its military build-up in the Middle East.
Washington is trying to negotiate a deal with Tehran over its nuclear program while threatening military action if talks fail.
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Fortification of nuclear facilities
Satellite images showed Iran recently erected a concrete shield over a new facility at a sensitive military site and covered it with soil, experts say, as work progressed at the site, which Israel allegedly bombed in 2024, amid tensions with the US.
According to Reuters, the images also showed Iran buried tunnel entrances at a nuclear site bombed by the US last year during Israel’s 12-day war with Iran, fortified tunnel entrances near another and repaired missile bases hit during the conflict.
Satellite images taken in late January showed new efforts to bury two tunnel entrances in the Isfahan compound, ISIS reported on January 29.
In a February 9 update, ISIS said a third entrance had also been filled with earth, meaning all entrances to the tunnel complex are now “completely buried,” Reuters reported.
The Isfahan complex is one of three Iranian uranium enrichment plants bombed by the United States in June.
A combination of satellite images showing the entrances to the tunnels at the Isfahan Nuclear Complex in Isfahan, Iran, before they were buried with earth, on November 11, 2024 (top) and afterwards, on February 10, 2026 (bottom). (via REUTERS)
ISIS also announced that satellite images showed ongoing efforts since February 10 to “consolidate and defensively strengthen” two entrances to a tunnel complex under a mountain about 2 km (1.2 miles) from Natanz – the site of Iran’s two other uranium enrichment plants.
The images further showed “ongoing activity throughout the complex related to this effort, involving the movement of numerous vehicles, including dump trucks, cement mixers and other heavy equipment,” ISIS wrote.
Structural repairs
In addition, a comparison of images taken on July 3, 2025 and January 30 showed reconstruction and clearance efforts at the main logistics and likely command base at the Shiraz South Missile Base, Reuters quoted William Goodhind, a forensic image analyst at Contested Ground, as saying.
A composite image of satellite imagery shows the Shiraz South missile base in Shiraz South, Iran, before renovation, July 3, 2025 (LEFT), and after renovation and clearance, January 30, 2026 (LEFT).(via REUTERS)
Meanwhile, a comparison of images taken between July 16, 2025 and February 1 shows a new roof over a damaged building near the Qom missile base.
A composite image of satellite imagery shows the Qom missile base building with a roof damaged by an airstrike in Qom, Iran, on July 16, 2025 (top), and the same site with a new roof, on February 1, 2026 (bottom). (via REUTERS)
According to CNN, satellite images of the Imam Ali missile base in Khorramabad, taken on January 5, showed that of the dozen structures destroyed by Israel, three have been rebuilt, one repaired and three more are currently under construction.
Two other military bases also underwent extensive repairs, CNN reported.
Taxiways and runways have been restored at the northwestern Tabriz airbase linked to Iran’s medium-range ballistic missiles.
In another, a missile base in the north of the city, extensive work was carried out after the war. All entrances have been reopened after being closed by bombing, the support area at the entrance has been largely rebuilt, and some tunnels are now open, according to an analysis by CNN and Sam Lair, a research associate at the James Martin Center for Non-Proliferation Studies (CNS).
At Hamadan Air Base in western Iran, craters left by bombs on the runway have been filled and aircraft fairings repaired, according to an analysis by CNN and Lair.
“The most important place is Shahrud”
Iran is also said to have rebuilt its largest and newest solid-propellant missile production facility at Shahroud, a technology that enables the rapid deployment of longer-range missiles.
“I think the most important place is Shahrud. The damage there was repaired very quickly,” Lair told CNN.
Naval exercise
Around February 17, Iran’s Revolutionary Guards conducted naval exercises in and around the Strait of Hormuz and said parts of the strategic waterway were closed for several hours. This happened when Iran and the US were holding indirect nuclear talks in Geneva.
According to Iranian media, the temporary restriction was related to the “Intelligent Control of the Strait of Hormuz” exercise and was aimed at ensuring safety and navigation principles during the exercise.
This handout photo released by the official Iranian Revolutionary Guards Corps (IRGC) website Sepanews on February 16, 2026 shows a ship firing a missile during a military exercise by members of the IRGC and the Navy in the Persian Gulf. Iran’s Islamic Revolutionary Guard Corps launched a series of military exercises in the Strait of Hormuz on February 16, state media reported, on the eve of talks with the United States. (AFP)
Tehran has repeatedly warned in the past that it could close the strait if attacked, a move that would disrupt one of the world’s most important oil export routes, Iran International said. This could cause major upheavals in the global energy market.
Guards Navy Commander Alireza Tangsiri said Iranian forces are ready to close the strait if ordered by the country’s leadership.
“The decision to close the Strait of Hormuz rests with senior leaders, and as a soldier I say we are ready to do it whenever our leaders say so,” Tangsiri said while overseeing the main phase of the exercise.
The drills reportedly began from Iran’s Gulf islands – including Abu Musa, Greater Tunb, Small Tunb and Sirri – which Iranian media have described as key positions for monitoring shipping there and western approaches to the Strait of Hormuz.
Reports said the exercise included elements of electronic warfare and simultaneous launches from land and sea.
Appointment of Ali Shamkhani
Tehran reportedly strengthened the Supreme National Security Council, headed by Khamenei confidant Ali Larijani, and created a new body – the Defense Council – for wartime government.
War veteran and former commander of the Islamic Revolutionary Guard Corps (IRGC) Ali Shamkhani, who survived an Israeli attempt on his life during last year’s war, was appointed secretary of Iran’s Supreme Defense Council this month.
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Shamkhani is an adviser to Supreme Leader Ayatollah Ali Khamenei. He was a naval admiral who had already served as deputy supreme leader in the Defense Council.
The aim of the move was to “comprehensively strengthen defense preparations” and develop “mechanisms to combat emerging threats,” Nour News, a portal linked to Iran’s security apparatus, reported according to CNN.