The US has imposed sanctions on Iran's extensive network of militia proxies in the Middle East.
Since the Islamic Revolution of 1979 that upended Iran's political and societal structure, the country has made a conscious effort to fan its influence across the Middle East with proxy groups.
The Quds Force, one of the five branches of the Islamic Revolutionary Guard Corps (IRGC) which specialises in intelligence and covert operations, serves as the main point of contact for these proxy groups, providing them with weapons and training to solidify Iran's regional agenda. Describing it as the "Axis of Resistance", over the years, Iran has built a network of proxies that have gone on to form major militias, some even developed into political parties, that challenge governments in their respective countries.
The Iranian Revolution's sphere of influence in its first decade was confined to Shi'a groups in Iraq, Lebanon, and the Gulf Emirates. It failed to make headways in countries with a majority Sunni population nor did its fundamentalist ideas entice Islamic militant groups.
Since 1984, and under six different presidents, the United States has imposed sanctions on Iran's extensive network of militia proxies in the Middle East in an effort to curb its regional influence. The Trump administration increased the pace and scope of these punitive economic measures between 2017 and 2021.
However, sanctions have never been fully successful. In 2020, the US State Department estimated that Iran provided $700 million per year to Hezbollah, the Lebanon-based group. In the past, Iran has historically provided $100 million annually to Palestinian groups, including Hamas and the Islamic Jihad.
So what are these groups and where do they operate:
Yemen
Sitting nearly 2,500 km away from Israel in Sanaa, Yemen's Houthis are the latest outside force that entered the Israel-Hamas war. The Yemeni rebel group claimed on Tuesday that they had fired drones and missiles at Israel.
Saudi Arabia and Bahrain, two kingdoms in the Persian Gulf, have long accused Iran of trying to sow discord in the region by inciting revolts among their Shia populations. In both countries, dissent has been suppressed with brutality. However, Iran succeeded in Yemen where the Houthi Shiite movement, armed and funded by the Revolutionary Guards, made rapid strides during the Yemeni civil war - which in itself is a protracted proxy war against Saudi Arabia and the United Arab Emirates.
The Houthi movement, which largely modelled itself on Hezbollah, was formed in the 1990s gained strength after 2014. The group's leadership is formed by the Houthi tribe and is currently led by Abdul-Malik Badruldeen al-Houthi.
Lebanon
Founded in the early 1980s, Hezbollah holds the distinction of being Iran's first proxy in the Middle East. The group is funded militarily and financially by the Revolutionary Guards. Hezbollah shares Tehran's Shiite Islamist ideals and recruits mostly among the Lebanese Shiite Muslims.
Hezbollah was formed to fight Israeli forces that had invaded Lebanon in 1982. It has routinely carried out suicide attacks against US personnel and its embassies in Lebanon. By 2020, Hezbollah, with at least 130,000 rockets and missiles, became the world's most heavily armed non-state actor, according to the Center for Strategic and International Studies.
Hezbollah maintains deep and close ties with other Iran-backed groups in the region including Hamas and the Islamic Jihad. Following the October 7 attacks on Israel by Hamas, and the subsequent Israeli retaliation, Hezbollah joined the fight "in solidarity" with the Palestinian people.
Syria
Syria's Assad family, a Shia offshoot, has long relied on its alliance with Iran to stay in power. This alliance has been especially beneficial since 2011, when President Bashar al-Assad faced an anti-government uprising and a civil war with Sunni extremists.
After Syria plummetted into chaos in 2011, Iran has been accused by Israel of providing around 80,000 fighting personnel to al-Assad's army while Russia provided air support.
In 2014, the Revolutionary Guards formed the Zaynabiyoun Brigade, a Pakistani Shiite militia group made up of Pakistanis living in Iran as well as the tribal areas of Pakistan, which fought alongside al-Assad's forces against rebel militias.
The Fatemiyoun Division, a group of Afghan Hazara fighters, was formed in the 1980s, ceased to exist in the 1990s, and was reestablished by the Revolutionary Guards in 2012. Since 2014, Iran has deployed the Fatemiyoun Division to Syria to fight for the Syrian government.
Iraq
Following the US invasion of Iraq in 2003, Iran expanded its influence on its former enemy, establishing loyal militias, gaining significant political clout, and reaping economic rewards.
In 2007, the Revolutionary Guards created the Kataib Hezbollah, a Shiite militia. US declared the Kataib Hezbollah as a 'Foreign Terrorist Organisation' in 2009 and sanctioned its Secretary General, Abu Mahdi al Muhandis, for violence against US-led coalition forces in Iraq.
In 2014, the Kataib Hezbollah joined Iraq's Popular Mobilization Forces (PMF) to fight Islamic State (IS) fighters but maintained close relations with the leadership in Tehran.
From 2007 to 2011 and again from 2018 to 2020, the Kataib Hezbollah, with Iran's backing, targetted US forces and its allies in Iraq with a series of sophisticated attacks. A 2019 rocket attack killed a US civilian contractor and injured four US soldiers at a military base in Kirkuk.
In 2006, the Revolutionary Guards and Hezbollah founded and trained the Asaib Ahl al Haq a Shiite militia. When the US recalled its forces from Iraq between 2006 and 2011, the group launched over 6,000 attacks on US and its allies. With around 20,000 personnel, the Asaib Ahl al Haq grew to become one of the largest Iran-backed militias in the region.
Similarly, the Revolutionary Guards armed and funded other Shiite groups in Iraq such as the Harakat Hezbollah al Nujaba, the Badr Organization and the Kataib Sayyad al Shuhada.
Gaza
In the Palestinian territories, Iran has for decades fought a shadow war against Israel. Hamas, the Palestinian group that carried out the October 7 attacks on Israel is believed to be funded by Tehran where it opened an office in the 1990s.
Relations between Iran and Hamas soured in 2012 after the Palestinian group refused to back the al-Assad regime in Syria. It led to Iraq temporarily cutting funding to Hamas before resuming it in 2017.
The Palestinian Islamic Jihad (PIJ) drew inspiration from the Iranian Revolution. According to the US State Department, it is Iran that funds the Islamic Jihad's budget, exactly like it reportedly does for Hamas and Hezbollah.
The US State Department said in 2020 that Iran provided more than $100 million annually to Palestinian groups.
Saudi Arabia
In 1987, the Revolutionary Guards founded the Shiite militant group Hezbollah al Hejaz in Saudi Arabia, one of Iran's primary political proponents in the Middle East. The US sanctioned four of its leaders for the deadly 1996 Khobar Tower bombing that killed 19 US Air Force personnel and Injured over 350 others.
The US Justice Department ordered Iran to pay $254 million to the families of the victims.
Bahrain
Funded and trained by Iran, the Al Ashtar Brigades is a militia based in the Gulf country of Bahrain. In 2014, the Al Ashtar Brigaded were behind the bomb attack that killed two police officers.