Hezbollah is a Lebanese Shia Islamist political party and militant group, led by its Secretary-General Hassan Nasrallah since 1992. Hezbollah's paramilitary wing is the Jihad Council, and its political wing is the Loyalty to the Resistance Bloc party in the Lebanese Parliament.
Jama'at al-Tawhid wal-Jihad, which may be abbreviated as JTJ or Jama'at, was a militant Jihadist group. It was founded in Jordan in 1999 and was led by Jordanian national Abu Musab al-Zarqawi for the entirety of its existence. During the Iraqi insurgency (2003–11), the group became a decentralized network with foreign fighters and a considerable Iraqi membership.
The Badr Organization, previously known as the Badr Brigades or Badr Corps, is an Iraqi Shia Islamist political party and military organization headed by Hadi Al-Amiri. The Badr Brigade was the Iran-officered military wing of the Iran-based Shia Islamic party, Supreme Council for Islamic Revolution in Iraq (SCIRI), formed in 1982. The Badr Brigade was created by Iranian intelligence and Shia cleric Mohammad Baqir al-Hakim with the aim of fighting Saddam Hussein's regime during the Iran–Iraq War. Since the 2003 US-led invasion of Iraq most of Badr's fighters have entered the new Iraqi army and police force. Politically, Badr Brigade and SCIRI were considered to be one party since 2003, but have now unofficially separated with the Badr Organization now an official Iraqi political party. Badr Brigade forces, and their Iranian commanders, have come to prominence in 2014 fighting the Islamic State of Iraq and the Levant (ISIL) in Iraq. It is a part of the Popular Mobilization Forces.
The 1920 Revolution Brigades is a Sunni militia group in Iraq, which includes former members of the disbanded Iraqi army. The group has used improvised explosive devices, and armed attacks against U.S./Coalition forces. The group comprises the military wing of the Islamic Resistance Movement. The group is named in reference to the Iraqi revolt of 1920.
The Mujahideen Shura Council (MSC), was an umbrella organization of at least six Sunni Islamic insurgent groups taking part in the Iraqi insurgency against U.S. and coalition and Iraqi forces: Tanzim Qaidat al-Jihad fi Bilad al-Rafidayn, Jaish al-Ta'ifa al-Mansurah, Katbiyan Ansar Al-Tawhid wal Sunnah, Saraya al-Jihad Group, al-Ghuraba Brigades, and al-Ahwal Brigades.
The term militia in contemporary Iraq refers to armed groups that fight on behalf of or as part of the Iraqi government, the Mahdi Army and Badr Organization being two of the biggest. Many predate the overthrow of Saddam Hussein, but some have emerged since, such as the Facilities Protection Service.
Hezbollah has a Foreign Relations Unit and maintains relations with a number of foreign countries and entities. These are particularly Shia states, but also Sunni groups like those affiliated with the Palestinian cause; and the group is also suggested to have operations outside the Middle East in places such as Latin America and North Korea.
Kata'ib Hezbollah —or the Hezbollah Battalions—is a radical Iraqi Shiite paramilitary group which is part of the Popular Mobilization Forces backed by Iran. During the Iraq War (2003–11), the group fought against Coalition forces. It has been active in the War in Iraq (2013–2017) and the Syrian civil war (2011–present). The group was commanded by Abu Mahdi al-Muhandis until he was killed by a US airstrike in Baghdad on 3 January 2020. Thereafter, he was replaced by Abdul Aziz al-Muhammadawi, as the new leader of the Popular Mobilization Forces (PMF).
Asa'ib Ahl al-Haq, also known as the Khazali Network, is a radical Iraqi Shi'a political party and paramilitary group active in the Iraqi insurgency and Syrian Civil War. During the Iraq War it was known as Iraq's largest "Special Group", and is now part of the Popular Mobilization Forces (PMF), a group of Shi’ite militias that are close to Iran.
The Army of the Men of the Naqshbandi Order, also called the Naqshbandi Army, is one of a number of underground Ba'athist and Sufi militant insurgency groups in Iraq. Media frequently refers to the group by the initials JRTN, a romanization of its Arabic name. Supreme Command for Jihad and Liberation, technically the name of the umbrella organisation to which JRTN belongs, is also often used to refer to JRTN specifically.
Between 2011 and 2017, fighting from the Syrian Civil War spilled over into Lebanon as opponents and supporters of the Syrian Arab Republic traveled to Lebanon to fight and attack each other on Lebanese soil. The Syrian conflict stoked a resurgence of sectarian violence in Lebanon, with many of Lebanon's Sunni Muslims supporting the rebels in Syria, while many of Lebanon's Shi'a Muslims supporting the Syrian government which is led by Bashar Al-Assad, whose Alawite minority is usually described as an offshoot of Shi'a Islam. Killings, unrest and sectarian kidnappings across Lebanon resulted.
The Mukhtar Army is a Shi'a Iraqi militia group formed in February 2013 by Wathiq al-Battat, a former senior official in the Hezbollah Brigades. Al-Battat pledged his loyalty to the Supreme Leader of Iran, Ayatollah Ali Khamenei. Al-Battat was arrested briefly on 2 January 2014 but was released despite still being a fugitive. He was apparently "accidentally assassinated" at point-blank range on 20 December 2014 at a fake police checkpoint in eastern Iraq by an unknown party.
The Islamic State of Iraq, commonly referred to as al-Qaeda in Iraq, was a militant Salafist jihadist group that aimed to establish an Islamic state in Sunni, Arab-majority areas of Iraq during the Iraq War and later in Syria during the Syrian Civil War.
Alwiya al-Furqan is an independent Islamist rebel group involved in the Syrian Civil War. It claimed to be the largest Islamist rebel faction that operated in the eastern Quneitra Governorate and Damascus. The group also held ties to Jordan which allowed fighters from the group to cross into the country to receive medical aid. During a sermon the group's leader stated that the Syrian opposition was building a Caliphate in Syria, that the rebels should emulate the Prophet Muhammad and his companions in doing so.
The military of the Islamic State is the fighting force of the Islamic State (IS). The total force size at its peak was estimated from tens of thousands to over two hundred thousand. ISIL's armed forces grew quickly during its territorial expansion in 2014. The ISIL military, including groups incorporated into it in 2014, openly operates and controls territory in multiple cities in Libya and Nigeria. In October 2016, it conquered the city of Qandala in Puntland, Somalia. It conquered much of eastern Syria and western Iraq in 2014, territory it lost finally only in 2019. It also has had border clashes with and made incursions into Lebanon, Iran, and Jordan. ISIL-linked groups operate in Algeria, Pakistan, the Philippines, and in West Africa. In January 2015, ISIL was also confirmed to have a military presence in Afghanistan and in Yemen.
Hezbollah involvement in the Syrian Civil War has been substantial since the beginning of armed insurgency phase of the Syrian Civil War in 2011, and evolved into active support for Ba'athist government forces and troop deployment from 2012 onwards. By 2014, Hezbollah was deployed across Syria. Hezbollah has also been very active in preventing Al-Nusra Front and Islamic State penetration into Lebanon, being one of the most active forces in the Syrian Civil War spillover in Lebanon.
The Popular Mobilization Forces (PMF), also known as the People's Mobilization Committee (PMC) and the Popular Mobilization Units (PMU), is an Iraqi state-sponsored umbrella organization composed of approximately 67 different armed factions, with around 128,000 fighters that are mostly Shia Muslim groups, but also include Sunni Muslim, Christian, and Yazidi groups. However, an investigation led by Former Prime Minister of Iraq, Haider al-Abadi revealed that approximately 60,000 are real soldiers, while the others 70,000 are "Ghost soldiers". The Popular Mobilization Units as a group was formed in 2014 and have fought in nearly every major battle against ISIL. It has been called the new Iraqi Republican Guard after it was fully reorganized in early 2018 by its then–Commander in Chief Haider al-Abadi, Prime Minister of Iraq from 2014 to 2018, who issued "regulations to adapt the situation of the Popular Mobilization fighters". Some of its component militias are considered terrorist groups by some states, while others have been accused of sectarian violence. During the 2019–2021 Iraqi protests, the organisation was accused of killing and wounding large numbers of protesters and activists.
Collaboration with the Islamic State refers to the cooperation and assistance given by governments, non-state actors, and private individuals to the Islamic State (IS) during the Syrian Civil War, Iraqi Civil War, and Libyan Civil War.
The history of the Islamic State of Iraq and the Levant (ISIL) began with the group's foundation in 1999 by Jordanian Salafi jihadist Abu Musab al-Zarqawi under the name Jamāʻat al-Tawḥīd wa-al-Jihād. In a letter published by the US State Department in February 2004, Zarqawi wrote that jihadists should use bombings to start an open sectarian war in Iraq so that Sunnis from other countries would mobilize against the assassinations carried out by Shias, specifically the Badr Organisation, against Ba'athists and Sunnis. The Islamic State would eventually grow to control territory with a population of millions.
Islamic State of Iraq and the Levant 
Lebanon 
Syrian Arab Republic 
Hezbollah 