Hezbollah in the context of "Iran–Israel proxy war"

Many states began to intervene against the Islamic State, in both the Syrian civil war and the War in Iraq (2013–2017), in response to its rapid territorial gains from its 2014 invasion of Iraq, universally condemned executions, human rights abuses and the fear of further spillovers of the Syrian civil war. In later years, there were also minor interventions by some states against IS-affiliated groups in Nigeria and Libya. All these efforts significantly degraded the Islamic State's capabilities by around 2019–2020. While moderate fighting continues in Syria, as of 2025, IS has been contained to a small area and force capability.

In mid-June 2014, Iran, according to American and British information, started flying drones over Iraq, and, according to Reuters, Iranian soldiers were in Iraq fighting IS. Simultaneously, the United States ordered a small number of troops to Iraq and started flying crewed aircraft over Iraq. In July 2014, according to the International Institute for Strategic Studies, Iran sent Sukhoi Su-25 aircraft to Iraq, and Hezbollah purportedly sent trainers and advisers to Iraq in order to help Shia militias to monitor IS's movements. In August 2014, the US and Iran separately began a campaign of airstrikes on IS targets in Iraq. Since then, fourteen countries in a US-led coalition have also executed airstrikes on IS in Iraq and in Syria. Starting from September 2014, United States began closely co-operating with Saudi Arabia and Jordan to wage a co-ordinated aerial bombing campaign against IS targets across Iraq and Syria.

From the 2000s until the fall of the Assad regime, the Islamic Republic of Iran and the Syrian Arab Republic were close strategic allies, and Iran provided significant support for the Syrian Ba'athist government in the Syrian civil war, including logistical, technical and financial support, as well as training and combat troops. Iran saw the survival of the Assad regime as being crucial to its regional interests. When the uprising developed into the Syrian civil war, there were increasing reports of Iranian military support, and of Iranian training of the National Defence Forces both in Syria and Iran. From late 2011 and early 2012, Iran's IRGC sent tens of thousands of Iranian troops and Shi'ite foreign paramilitary volunteers in coordination with the Syrian government to prevent the collapse of the regime; thereby polarizing the conflict along sectarian lines.

Iranian security and intelligence services advised and assisted the Syrian military in order to preserve the erstwhile Syrian President Bashar al-Assad's hold on power. Those efforts included training, technical support, and combat troops. Estimates of the number of Iranian personnel in Syria ranged from hundreds to tens of thousands. Lebanese Hezbollah fighters, backed by Iran's government, had taken direct combat roles from 2012 until 2024. From the summer of 2013, Iran and Hezbollah provided important battlefield support for Assad, allowing it to make advances on the opposition.

The Blue Line is a demarcation line dividing Lebanon from Israel and the Golan Heights. It was published by the United Nations on 7 June 2000 for the purposes of determining whether Israel had fully withdrawn from Lebanon. It has been described as "temporary" and "not a border, but a “line of withdrawal”. It is the subject of an ongoing border dispute between Israel, Lebanon, and Hezbollah.

On 19 March 1978, the United Nations Security Council adopted Resolutions 425 and 426 calling for Israeli withdrawal from Lebanon following its recent invasion and to ensure that the government of Lebanon restores effective authority in the area to the border. The United Nations Security Council and NATO set up the United Nations Interim Force in Lebanon (UNIFIL) as a peacekeeping force to supervise the situation in Southern Lebanon.

The Israeli occupation of Southern Lebanon lasted for eighteen years, from 1982 until 2000. In June 1982, Israel invaded Lebanon in response to attacks from southern Lebanon by Palestinian militants. The Israel Defense Forces (IDF) occupied the southern half of Lebanon as far as the capital city Beirut, together with allied Maronite Christian paramilitaries involved in the Lebanese Civil War. The IDF left Beirut on 29 September 1982, but continued to occupy the country's southern half. Amid rising casualties from guerrilla attacks, the IDF withdrew south to the Awali river on 3 September 1983.

From February to April 1985, the IDF carried out a phased withdrawal to a "Security Zone" along the border, which it said was to protect northern Israel. From this point onwards, Israel supported the South Lebanon Army (SLA), the Lebanese Christian paramilitary, against Hezbollah and other Muslim militants. They fought a guerrilla war in Southern Lebanon throughout the occupation.

The 2006 Lebanon War was a 34-day armed conflict in Lebanon, fought between Hezbollah and Israel. The war started on 12 July 2006, and continued until a United Nations-brokered ceasefire went into effect in the morning on 14 August 2006, though it formally ended on 8 September 2006 when Israel lifted its naval blockade of Lebanon. It marked the third Israeli invasion into Lebanon since 1978.

After Israel's withdrawal from southern Lebanon in 2000, Hezbollah aimed for the release of Lebanese citizens held in Israeli prisons. On 12 July 2006, Hezbollah ambushed Israeli soldiers on the border, killing three and capturing two; a further five were killed during a failed Israeli rescue attempt. Hezbollah demanded an exchange of prisoners with Israel. Israel launched airstrikes and artillery fire on targets in Lebanon, attacking both Hezbollah military targets and Lebanese civilian infrastructure, including Beirut's Rafic Hariri International Airport. Israel launched a ground invasion of Southern Lebanon and imposed an air-and-naval blockade on the country. Hezbollah then launched more rockets into northern Israel and engaged the IDF in guerrilla warfare from hardened positions. According to Israeli sources, Hezbollah fired close to 4,000 rockets and missiles at Israel from their arsenal of around 15,000 held before the war.

TWA Flight 847 was a regularly scheduled Trans World Airlines flight from Cairo to San Diego with en route stops in Athens, Rome, Boston, and Los Angeles. On the morning of June 14, 1985, Flight 847 was hijacked soon after take off from Athens. The hijackers demanded the release of a total of 784 Shia Muslims from Israeli custody and took the plane repeatedly to Beirut and Algiers. After the incident, Western analysts asserted that hijackers had been members of Hezbollah, however, Hezbollah refutes that claim to this day.

The hijacking and subsequent hostage situation played out over the course of 17 days, during which the aircraft crisscrossed the Mediterranean. Many passengers were tied up and beaten, and those with Jewish-sounding names were separated from the others. United States Navy diver Robert Stethem was murdered, and his body was thrown onto the Beirut airport apron. The ordeal finally ended after some of the hijackers' demands had been met and they agreed to release all remaining hostages. Many believed that due to the lawless nature of Lebanon at the time the captors would go unpunished.

The United Nations Interim Force in Lebanon (Arabic: قوة الأمم المتحدة المؤقتة في لبنان; Hebrew: כוח האו"ם הזמני בלבנון), or UNIFIL (Arabic: يونيفيل; Hebrew: יוניפי״ל) is a United Nations peacekeeping mission established on 19 March 1978 by United Nations Security Council Resolutions 425 and 426, and several further resolutions in 2006 to confirm Hezbollah demilitarisation, support Lebanese army operations against insurgents and weapon smuggling, and confirming Israeli withdrawal from Lebanon, in order to ensure that the government of Lebanon would restore its effective authority in the area. The 1978 South Lebanon conflict came in the context of Palestinian insurgency in South Lebanon and the Lebanese Civil War.

The mandate had to be adjusted due to the Israeli invasion of Lebanon in 1982 and after the Israeli withdrawal from Lebanon in 2000. Following the 2006 Lebanon War, the United Nations Security Council enhanced UNIFIL and added additional tasks to the mandate such as aiding displaced persons.

The Iran–Israel war (13 June – 24 June 2025), also known as the Twelve-Day War, was an armed conflict in the Middle East. The war began when Israel bombed military and nuclear facilities in Iran in a surprise attack, assassinating prominent military leaders, nuclear scientists, and politicians, killing civilians, and damaging or destroying air defenses. Iran retaliated with over 550 ballistic missiles and over 1,000 suicide drones, hitting civilian population centers, one hospital and at least twelve military, energy, and government sites. The United States intercepted Iranian attacks, and bombed three Iranian nuclear sites on 22 June. Iran retaliated by firing missiles at a US base in Qatar. On 24 June, Israel and Iran agreed to a ceasefire under US pressure.

The war followed a decades-long proxy war. Iran has called for Israel's destruction, and armed Hamas in Gaza and Hezbollah in Lebanon. Following the October 7 attacks in 2023, both entered open conflict with Israel. In April 2024, Israel bombed Iran's consulate in Damascus, Syria, killing senior Iranian military officials. Direct conflict continued in April and October. Iran's nuclear program has caused international concern for over a decade. Israel considers it an existential threat. In 2015, under the Joint Comprehensive Plan of Action (JCPOA), six countries lifted sanctions on Iran, which froze its nuclear program. In 2018, US president Donald Trump unilaterally withdrew from the plan. Iran began stockpiling enriched uranium and largely suspended International Atomic Energy Agency (IAEA) monitoring. The day before Israel attacked, the IAEA declared Iran non-compliant with its nuclear obligations in a resolution put forward by the United States, United Kingdom, France, and Germany.

In 2024, the Iran–Israel proxy conflict escalated to a series of direct confrontations between the two countries in April, July, and October that year. On 1 April, Israel bombed an Iranian consulate complex in Damascus, Syria, killing multiple senior Iranian officials. In response, Iran and its Axis of Resistance allies seized the Israeli-linked ship MSC Aries and launched strikes inside Israel on 13 April. Israel then carried out retaliatory strikes in Iran and Syria on 19 April.

On 31 July, Hamas political leader Ismail Haniyeh was assassinated, in Tehran, Iran. The killing of Haniyeh occurred a few hours after the 2024 Haret Hreik airstrike in Lebanon that assassinated Hezbollah commander Fuad Shukr.

Since the Iranian Revolution in 1979, the government of the Islamic Republic of Iran has been accused by several countries of training, financing, and providing weapons and safe havens for non-state militant actors, such as Hezbollah in Lebanon, Hamas in Gaza, and other Palestinian groups such as the Islamic Jihad (IJ) and the Popular Front for the Liberation of Palestine (PFLP). These groups are designated terrorist groups by a number of countries and international bodies such as the EU, UN, and NATO, but Iran considers such groups to be "national liberation movements" with a right to self-defense against Israeli military occupation. These proxies are used by Iran across the Middle East and Europe to foment instability, expand the scope of the Islamic Revolution, and carry out terrorist attacks against Western targets in the regions. Its special operations unit, the Quds Force, is known to provide arms, training, and financial support to militias and political movements across the Middle East, including Bahrain, Iraq, Lebanon, Palestine, Syria, and Yemen.

A number of countries (Argentina, Albania, Australia, Bulgaria, Denmark, France, India, Kenya, Sweden, Thailand, United States) have accused the Iranian government and the Islamic Revolutionary Guards Corps of plotting assassinations or bombings in their countries and others against perceived enemies of Iran. In response, economic sanctions against the Iranian regime have been imposed by many countries and the United Nations. The first sanctions were imposed by the United States in November 1979, after a group of radical students seized the U.S. embassy in Tehran and took hostages. The sanctions were expanded in 1995 to include business dealings with the Iranian government. However, these sanctions have not significantly impacted the country's relationships with its proxies. The United States Department of State estimated that Iran spent more than $16 billion in support of the Assad regime and its proxies between 2012 and 2020, a period in which Iran funneled more than $700 million to Hezbollah.

Hay'at Tahrir al-Sham (HTS) was a Sunni Islamist political organisation and paramilitary group involved in the Syrian civil war. It was formed on 28 January 2017 as a merger of several armed groups: Jaysh al-Ahrar (an Ahrar al-Sham faction), Jabhat Fateh al-Sham (JFS), Ansar al-Din Front, Jaysh al-Sunna, Liwa al-Haqq and the Nour al-Din al-Zenki Movement. The unification process was held under the initiative of Abu Jaber Sheikh, an Islamist militant commander who had been the second emir of Ahrar al-Sham. HTS, along with other Syrian opposition groups, launched an offensive that led to the fall of the Assad regime on 8 December 2024.

Proclaiming the nascent organisation as "a new stage in the life of the blessed revolution", Abu Jaber Sheikh urged all factions of the Syrian opposition to unite under its Islamic leadership and wage a "popular jihad" to achieve the objectives of the Syrian revolution, which he characterised as the ouster of the Ba'athist regime and Hezbollah militants from Syrian territories, and the formation of an Islamic government. After the announcement, additional groups and individuals joined. The merged group has been primarily led by Jabhat Fatah al-Sham and former Ahrar al-Sham leaders, although the High Command also has representation from other groups. The Nour al-Din al-Zenki Movement split from Tahrir al-Sham in July 2017, and the Ansar al-Din Front in 2018.

On 14 February 2005, former Prime Minister of Lebanon Rafic Hariri was assassinated along with 21 others in an explosion in Beirut, Lebanon. Explosives equivalent to around 1,000 kilograms (2,200 pounds) of TNT were detonated as his motorcade drove near the St. George Hotel. Among the dead were several of Hariri's bodyguards and former Minister of Economy and Trade, Bassel Fleihan.

Hariri had been part of the anti-Assad opposition in Lebanon. His assassination triggered the Cedar Revolution, a popular movement which forced Syria to withdraw all its troops in Lebanon by April 2005. The United Nations set up the Special Tribunal for Lebanon to investigate the killing, which along with an independent investigation carried out by Lebanese Brigadier General Wissam al-Hassan, found compelling evidence that Hezbollah carried out the assassination. One of the investigators, Wissam Eid, was assassinated in 2008.

The Rezgari Party or Razkari Party (Arabic: حزب رزكاري, romanized: Ḥizb Rizkārī; Kurdish: حزبی ڕزگاری, romanized: Ḧizbî R̄izgarî) is a Lebanese-Kurdish political group that was established on 3 April 1975 by Faysal Fakhru, due to disagreement with the policies of the Kurdish Democratic Party – Lebanon (KDP-L) under Jamil Mihhu. The three main points of disagreement that led to the formation of the Rezgari Party were the KDP-L's failure to appeal to non-Kurmanji-speaking Kurds, its support for the Iraqi government's proposals in the Iraqi–Kurdish conflict, and accusations of nepotism within the party's leadership. The Rezgari Party continued to exist following the end of the Lebanese Civil War, becoming the only political party to represent Lebanon's estimated 100,000 Kurds, and aligning itself with Hezbollah and the March 8 Alliance.

The Islamic Republic of Iran is a key patron of the Lebanese Shia Islamist militia and political party Hezbollah.

Iranian support, including financial aid, deployment of Revolutionary Guards, and training, has played an important role in Hezbollah's formation and development. Hezbollah has functioned as Iran's proxy since its inception, and is considered to be part of the "Axis of Resistance".

The South Lebanon conflict was an armed conflict that took place in Israeli-occupied southern Lebanon from 1982 or 1985 until Israel's withdrawal in 2000. Hezbollah, along with other Shia Muslim and left-wing guerrillas, fought against Israel and its ally, the Catholic Christian-dominated South Lebanon Army (SLA). The SLA was supported militarily and logistically by the Israel Defense Forces (IDF) and operated under the jurisdiction of the Israeli-backed South Lebanon provisional administration, which succeeded the earlier Israeli-backed Free Lebanon State. Israel officially names the conflict the Security Zone in Lebanon Campaign and deems it to have begun on 30 September 1982, after the end of its "Operation Peace for Galilee". It can also be seen as an extension of the Lebanese Civil War (1975–1990).

Israel invaded Lebanon in 1978 and in 1982, to end the Palestinian insurgency in South Lebanon and support Lebanese Maronite Christians in the Lebanese Civil War. The 1982 invasion resulted in the Palestine Liberation Organization (PLO) leaving Lebanon and marked the beginning of Israeli occupation. Militant groups began attacking Israeli forces in southern Lebanon in September 1982. Amid rising casualties from guerrilla attacks, the IDF retreated south of the Awali river on 3 September 1983. The IDF began a phased withdrawal from Lebanon in February 1985. It withdrew to a "security zone" along the border on 29 April, and most IDF troops withdrew from the "security zone" on 10 June. A small number of IDF soldiers remained in the zone to support the SLA. Throughout its existence, there were about 1,500 IDF and 2,500 SLA troops in the "security zone" at any given time.