The Wall Street Journal has reported that the Islamic Republic has resumed the production of ballistic missiles at underground facilities. Farzin Nadimi, senior research fellow for defense and security affairs, said that this move, given the vulnerability of ground-based facilities in expected airstrikes, was to be expected, and that the activities are in both solid-fuel and liquid-fuel missile fields.

He added that technical limitations and the high risk involved in producing solid fuel may have led the Islamic Republic to focus more for now on producing liquid-fuel missiles, and that much of the process of preparing these missiles can also be carried out in underground tunnels.