The killing of Iranian general Qassem Suleimani in a US airstrike in Iraq on 3 January has significantly increased tensions between the two nations, with a significant probability of retaliation or possible escalation by Iran. In addition to conventional military means, Iran has an array of non-state proxy groups across the broader region that could potentially be utilised to threaten US military and government targets.
Better known as the Houthis, Ansar Allah has been provided with both arms, training, and manpower by Iran. The most serious threat potentially posed is to international shipping – particularly oil tankers – traversing the Bab al-Mandab strait, with the group having deployed both anti-ship missiles and explosives-laden unmanned maritime vehicles (UMV) against sea vessels previously.
In the event of either an escalation of hostilities between Iran and the US, or as an act of retaliation for Suleimani’s killing, the Iranians could utilise Ansar Allah, or its own forces likely stationed alongside the group in Yemen, to target and threaten tankers transporting oil to the US. There is also the risk of the use of ballistic missiles and weaponized unmanned aerial vehicles (UAV) to target US military personnel, assets, or facilities at bases in Saudi Arabia.
The military wing of Lebanese group Hizbullah, al-Muqawama al-Islamiyya, has been extensively armed, trained, financed, and supplied by Iran since its inception, and represents Iran’s most operationally-proficient proxy. Hizbullah forces are present in both Syria and Iraq alongside Iranian-backed Shia militia groups and could directly target US forces/interests in either countries as either retaliation or an escalation of hostilities.
Separately, Hizbullah and the IRGC-Quds Force were blamed by Israel for a series of attacks targeting its interests in Azerbaijan, Cyprus, Egypt, Georgia, India, Thailand, Turkey, and the US between 2010-12, highlighting a potential capacity to strike US interests beyond the immediate region. While US officials have repeatedly highlighted an alleged Hizbullah presence in South America, it remains unclear to what extent, if any, this represents any potential operational capacity for attacks either regionally against US interests or targeting the US directly.
In Iraq and Syria, the IRGC has funded, armed, and supported a broad range of Shia militias to fight as its proxies in the territorial campaign against the Islamic State and as part of the broader conflict in Syria. In addition to domestic Shia militias in Iraq (broadly operating under the aegis of the Hashd al-Shaabi) and Syria, Iran has also funded, armed, and facilitated the involvement of Afghan and Pakistani Shia militias in the conflict in Syria. These forces could directly attack remaining US military forces in northeast Syria or target US military or government individuals and facilities in Baghdad. This would most likely take the form of indirect fire attacks on static bases and positions, with a lower potential for a direct assault on US military positions.
A secondary, but lesser, threat would also be posed to US military and government personnel and interests in Afghanistan and Pakistan by returnee Shia militiamen.
9 January 2020, Matthew Henman, head of Janes Terrorism and Insurgency Centre (JTIC)