by Asad Mirza
Iran’s decentralised “Mosaic Defence” strategy and layered “Fourth Successor” leadership model are designed to sustain military operations and governance despite decapitation strikes or leadership losses.
In the ongoing war against Iran by the United States and Israel, two terms that have gained prominence are the “Mosaic Defence” model of war tactics and the “Fourth Successor” model of leadership, both of which have, so far, demonstrated the resilience of the Iranian regime in the conflict.
As the US–Israel versus Iran conflict intensifies, Iran’s decentralised “Mosaic Defence” and “Fourth Successor” layered leadership models ensure that military operations persist despite leadership losses.
The world first heard the term in Iranian Foreign Minister Seyed Abbas Araghchi’s post on X on March 1, when he wrote, “…decentralised Mosaic Defence enables us to decide when—and how-war will end.”
Two key pillars of Iran’s strategy were put forth here: first, observing and adapting to US military weaknesses, and second, complete decentralisation of its command and control to ensure resilience and continuity in the event of decapitation strikes.
Mosaic Defence
The decentralised defence strategy referred to here by Araghchi, dubbed “Mosaic Defence,” seeks to neutralise the impact of US or Israeli strikes targeting its leadership or command-and-control structures, and to ensure continuity in the face of any decapitation strike.
Sometimes referred to as “salami slicing” tactics, this approach extends to Iran’s goal of bleeding the US and Israel economically, in an effort to bring the war home to their respective populations and ensure that the war remains unpopular domestically for Tehran’s foes.
Iran’s defence doctrine, playing out in real time since the start of Operation Epic Fury, has been decades in the making and was cemented by the Iran–Iraq War (1980–88) as well as the Israeli invasion and occupation of Lebanon during the Lebanese Civil War. Both were formative in shaping how Iran and its primary proxy group, Hezbollah, view the current conflict.
Further, this three-pronged defence doctrine evolved in 2005, when the Islamic Revolutionary Guard Corps (IRGC), under the supervision of Mohammad Ali Jafari, announced its model of “Mosaic Defence”—essentially a decentralised command-and-control system.
In an analysis by Michael Connell, this strategy led directly to the restructuring of the IRGC command-and-control architecture into a system of 31 separate commands. These could launch an insurgency in the case of invasion and would make any attempt to degrade Iran’s defence exceedingly difficult.
According to a report by the RAND Corporation, Iraqi forces in 2003 were paralysed by a command structure highly centralised around Iraqi dictator Saddam Hussein. This structure prevented both the regular Iraqi Army and the Republican Guard units from coordinating effectively, while officers at the division and corps level could not conduct even basic manoeuvres without Saddam’s approval.
The 2010 report notes that the rapid defeat of Saddam Hussein’s regime made Jafari and other Iranian officials realise the need to ensure that the IRGC and the regular Iranian armed forces—the Islamic Republic of Iran Army, could operate independently and not collapse upon losing contact with higher command.
According to the RAND Corporation, Iran’s “Mosaic Doctrine” was first formulated in 2005, when Jafari, as director of the IRGC’s Center for Strategic Studies, identified two critical threats to the regime of the Ayatollahs: “a foreign attempt to foment a ‘soft revolution’ through support of Iranian NGOs and activists, and a US military attack that could topple the regime.”
Iran began implementing the doctrine in 2005, accelerating after Jafari is appointed IRGC Commander-in-Chief in 2007. A 2010 report by the United States Institute of Peace confirms this development.
According to a report by The Soufan Centre, the Mosaic Doctrine emphasised layered, distributed defences designed to exploit Iran’s geography—its rugged mountains, vast interior and dispersed population centres, and enable prolonged resistance against superior invading forces.
The core innovation was the restructuring of the IRGC into 31 semi-autonomous provincial commands, one per province. Each command functions as a self-contained entity with independent headquarters, command-and-control nodes, missile and drone arsenals, integrated Basij militia units, fast-attack naval flotillas, intelligence assets, stockpiled munitions and pre-delegated authority for contingency operations.
After assuming command of the IRGC in 2007, Jafari oversaw the doctrine’s full implementation, integrating Basij forces into the IRGC and strengthening asymmetric capabilities.
This decentralisation, approved under the late Supreme Leader Ali Khamenei, allowed local commanders broad freedom of action to pursue strategic objectives without real-time central oversight.
This approach echoes mission-type tactics similar to the German Auftragstaktik doctrine which, according to research by the U.S. Naval Institute, allows subordinate officers freedom to act as they see fit so long as they achieve the objectives set by their superiors.
In practical terms, the military is designed to keep functioning even if the “head” of the system is removed.
The “Fourth Successor” Leadership Model
Meanwhile, Iran has also developed a layered leadership system designed to prevent a power vacuum during wartime.
The concept, sometimes referred to as the “Fourth Successor,” ensures that multiple levels of leadership are prepared to assume authority if senior figures are killed in a conflict.
Iranian planners have long expected that in a war with powerful adversaries such as the United States or Israel, top leaders, including the supreme leader, could be targeted.
To prevent disruption, the state has maintained a deep hierarchy of leadership so that authority can pass down several levels without interrupting governance or military command.
Under Iran’s political system, the Assembly of Experts is responsible for selecting the supreme leader. If the sitting leader dies or becomes incapacitated, an interim leadership council can temporarily perform the responsibilities of the office while a permanent successor is chosen.
A version of this arrangement was briefly seen after the killing of Ali Khamenei. During that period, a three-member council that included Masoud Pezeshkian and other senior officials handled leadership duties until a new supreme leader was appointed.
The “Fourth Successor” idea builds on this mechanism. It ensures that additional figures are prepared to assume authority if the supreme leader and the immediate successors are eliminated.
This layered system is meant to guarantee that the state, particularly its security and military apparatus, continues to function regardless of leadership losses.
Overall, the current confidence of the Iranian leadership could be attributed to the success of its “Mosaic Defence” and “Fourth Successor” leadership models, about which its adversaries had little operational understanding.
(The writer is a New Delhi-based senior commentator on national, international, defence and strategic affairs, environmental issues, an interfaith practitioner, and a media consultant. Ideas are personal.)
