As tensions mount over a potential US-Israeli confrontation with Iran, analysts warn that Tehran’s most decisive line of defence lies not only in missiles and drones, but in its deeply embedded internal security structure.

At the centre of this architecture stands the Basij force, a nationwide network designed to prevent internal unrest and ensure regime stability during times of war and crisis.

External Threats and Internal Scenarios

As the possibility of a US-Israeli military confrontation with Iran continues to be discussed in international political and security circles, attention has largely focused on Tehran’s missile capabilities, drone technology and regional allies. However, Iran’s defence doctrine is not limited to external deterrence. A central, and often underestimated, pillar of this strategy is its internal security architecture — with the Basij force playing a decisive role.

According to journalist and Iran analyst Ramazan Bursa, Iran prepares for conflict based on worst-case scenarios, including the prospect of a foreign military attack coinciding with internal unrest. In such a scenario, the most critical responsibility for maintaining domestic stability would fall not on the regular army or police alone, but on the Basij, a volunteer paramilitary organisation operating under the Islamic Revolutionary Guard Corps (IRGC).

Two Possible Internal Outcomes

Bursa notes that Iranian decision-makers assess two main internal scenarios in the event of a US-led attack.

The first scenario involves widespread uprisings erupting simultaneously across major cities, driven by separatist armed groups, opposition networks linked to the People’s Mujahedin Organisation, pro-Pahlavi elements, and covert foreign intelligence operatives.

The second scenario envisages broad social segments — including reformists, secular groups, tribes and political factions — rallying behind the state in opposition to foreign aggression. In such a case, opposition groups may refrain from mass mobilisation, calculating that street action would not yield the desired results.

Iran’s internal defence planning is structured to confront both possibilities.

Iran’s Internal Defence Doctrine

While Iran’s external response relies on ballistic and hypersonic missiles, drones and regional strike capabilities, internal containment is entrusted primarily to the Basij’s nationwide, decentralised structure.

Founded in 1979 on the directive of Ayatollah Ruhollah Khomeini, the Basij emerged as a mass volunteer force during the Iran-Iraq War, where it suffered heavy casualties and became deeply embedded in the revolutionary narrative. Today, it functions as a hybrid organisation combining military, ideological, social and cultural roles.

Estimates place Basij membership at around 20 million, organised down to neighbourhood and village levels across the country.

Organisational Structure and Social Penetration

The Basij’s organisational model divides cities into “resistance zones,” neighbourhoods and stations, allowing for rapid mobilisation and localised control. Its presence spans universities, schools, factories, mosques, rural areas and urban districts, giving it a level of social penetration unmatched by conventional security forces.

Members are classified as basic, active or special forces, depending on training level and operational readiness. While most Basij members do not receive regular salaries, elite units operate professionally and are directly integrated into IRGC command structures.

Brigades and Operational Units

Operationally, the Basij is organised through several specialised brigades, each assigned distinct roles:

• Ashura Brigades focus on unrest prevention, crowd control and soft-power activities among men.
• Zahra and Kowsar Brigades mobilise women in social, cultural and security roles.
• Beyt al-Maqdis Brigades are tasked with suppressing civil unrest and securing cities and villages.
• Imam Ali Brigades are regarded as the most decisive force for counter-insurgency and emergency internal security operations.
• Imam Hussein Brigades, composed of professional fighters, focus on external threats and have played a role in overseas deployments, particularly in Syria.

This layered structure enables Iran to respond flexibly to varying threat levels.

Communication and Rapid Mobilisation

A key element of the Basij’s effectiveness is its internal communications network. Platforms such as the SHABAB system allow commands to be transmitted rapidly from central leadership to local units, ensuring swift coordination during crises.

During the 12-day Iran-Israel confrontation, this system reportedly played a crucial role in identifying and neutralising internal threats and sabotage attempts, significantly reducing the pace of attacks originating from within Iran.

Ideological Discipline and Salihin Circles

Ideological cohesion is reinforced through units such as the Salihin Circles, which organise members by age group and provide continuous political and religious indoctrination.

These circles function as mobilisation hubs and loyalty-building mechanisms, ensuring alignment with the Supreme Leader’s directives and maintaining discipline at the grassroots level.

How the Global Media Frames the Basij

International media coverage typically portrays the Basij as a force used to suppress protests and maintain regime control. Western reporting often frames it narrowly through a human-rights lens.

However, Iranian and regional analyses describe the Basij as an essential component of a broader “mosaic defence” doctrine — a system designed to fragment threats, deny rapid territorial gains to adversaries and prevent internal collapse during external aggression.

Conclusion: A Decisive Pillar of Internal Security

Assessing Iran’s security posture solely through its military hardware or regular forces provides an incomplete picture. The Basij represents a deeply embedded, multi-functional structure capable of rapid mobilisation, territorial control and ideological enforcement.

In any scenario where external attack and internal unrest converge, the existence of such an organisation significantly reduces the likelihood of swift internal destabilisation.

For this reason, analysts argue that the Basij remains one of the most decisive elements in Iran’s internal defence architecture — making large-scale uprisings during wartime extremely difficult to sustain and limiting the strategic options of Iran’s adversaries. (ILKHA)