When the US and Israel struck Iran on February 28, they probably expected the Islamic Revolutionary Guard Corps (IRGC) to fold quickly. However, Tehran had spent two decades studying US wars to build a system that could keep fighting even if the capital was bombed.
At the centre of Iran's defence doctrine is what Tehran's military thinkers call “decentralised mosaic defence”. This concept is built on the assumption that Iran may lose senior commanders, key facilities, communications networks and even centralised control in any war with the United States or Israel, but must still be able to keep fighting.
Under the doctrine, neither the defence of Tehran is of key importance nor is the protection of the leadership. The priority is preserving decision-making, keeping combat units operational and preventing the war from ending with a single devastating strike.
The concept of 'Mosaic defence' is most closely associated with the IRGC, particularly under former commander Mohammad Ali Jafari, who led the Iranian force from 2007 to 2019.
Iran's defence units, including the IRGC, the Basij, regular army units, missile forces, naval assets and local command structures, form parts of a distributed system. If one of the structures is hit, others keep functioning.
The chain of the military remains intact even if senior leaders are killed, and local units still retain the authority and capacity to act even if communications with the central command are cut off.
