Iran builds 'defensive tunnel' in Tehran to avoid future Israeli attacks

Iran is building what it termed a “defensive tunnel” in the capital Tehran, the semi-official Tasnim news agency reported on Tuesday, following two counter-strikes by Israel on Iran, including one last month.

Israel’s air force counter-attacked Iran on April 19 and, in a much larger series of strikes, on October 26, after the Islamic Republic launched two massive aerial attacks on the Jewish state on April 13-14 and October 1.

Tehran attacked Israel with over 300 aerial threats, including around 120 ballistic missiles in April and with around 180 ballistic missiles on October 1.

The air force responded on April 19 by destroying Iran’s S-300 anti-aircraft missile defense system, which was guarding its Natanz nuclear facility, and on October 26 by destroying four more critical S-300 systems, including sites related to Iranian ballistic missile production.

According to the Tasnim report, the tunnel, located near the city center, will link a station on the Tehran metro to Imam Khomeini Hospital, thus allowing direct underground access to the medical facility.

“For the first time in the country, a tunnel with defensive applications is being built in Tehran,” the head of transport for Tehran City Council told Tasnim.

Examining Iran's broader, longer-term strategy of underground fortifications

Although the initiative seems to be new, it could reflect Iran’s broader and longer-term strategy of using underground fortifications, which it has been using and expanding for years.

As early as 2006, Iran built a secret nuclear facility under a mountain at Fordow, which the West only exposed in 2009.

There is speculation that, absent the facility’s exposure, Tehran might have tried to use the facility to clandestinely break out a nuclear weapon.

In any case, Iran hoped that by building the facility underground, Israel would be unable to attack it, even if it wanted to.

In 2021, Iran started to build a second nuclear facility underground, under a mountain at Natanz.

Iran built its conventional ballistic missile facilities and various air force assets underground at a number of other locations to protect them from attacks.

This was also done to make it more difficult for Jerusalem or Washington to attack various strategic sources of Iranian military power.

Although Iran called the new tunnels defensive and focused on connecting a hospital to a metro station, neither of Israel’s two attacks on Iran struck a single civilian location.

Rather, if the latest announcement follows previous Iranian actions, it could be cover for moving more and more of its nuclear, military, and governing capabilities, as well as the ability to move assets in those fields around, underground.

Such moves will make them harder to strike and allow the movement of assets beyond the sight of Israel’s and the US’s satellites.

During the weeks when Israeli and other defense experts debated whether Israel should strike Iran’s nuclear program or less important assets, one of the concerns was that if Jerusalem struck but did not hit the nuclear program, Tehran might decide to move its nuclear assets further out of reach, such as underground.

The latest announcement could be a manifestation of this process.