SUMMARY

The Republic of Yemen, formerly North Yemen, is the poorest country in the Arabian Peninsula and has witnessed escalating violence since the authoritarian president of Yemen of 33 years, Ali Abdullah Saleh, was forced to step down after massive protests during the Arab Spring in 2011.

The situation in the country deteriorated sharply as an intrastate conflict with Ansarallah (widely referred to as Houthis) broke out anew in 2014-2015. The capital Sanaa was captured by Ansarallah and the government of Abdrabbuh Mansur Hadi was ousted on 22 January 2015. Ansarallah thus became the new Government of Yemen by controlling the capital, according to UCDP definitions. A conflict over government against the Forces of Hadi broke out after Hadi fled from Sanaa to Aden, and rescinded his resignation. Hadi finally resigned in April 2022, and was replaced by an eight-man Presidential Leadership Council, causing the main opposition coalition, formerly the Forces of Hadi, to be renamed the Forces of the Presidential Leadership Council.

Since 2015, Yemen has been embroiled in an internationalized civil war, during which the Forces of the Presidential Leadership Council has received widespread support from a coalition of Arab states led by Saudi Arabia. Several more state-based and non-state conflicts has erupted along the sidelines of the Government of Yemen - Forces of the Presidential Leadership Council conflict, mainly involving AQAP, Islamic State (IS) and the separatist movement Southern Transitional Council (STC). Access to reliable information about the number of fatalities has remained limited throughout the conflict, and the numbers should be seen as conservative lows. The conflicts have fuelled one of the worst humanitarian crisis in the world amidst widespread famine and disease outbreaks.

Since 1989, Yemen has experienced the intrastate, non-state and one-sided categories of UCDP organized violence. Below follows a summary of the main events in the country since; for a more detailed account go to the respective conflict or actor pages.

2025

Violence in the state-based conflict over government between the Ansarallah Government of Yemen and Forces of the Presidential Leadership Council decreased for the fourth consecutive year in 2025. Violence fell sharply after a ceasefire was agreed upon between the main warring parties on 2 April 2022. Despite the ceasefire formally expiring on 2 October 2022, it continued being maintained informally throughout 2023, 2024 and 2025. Violence has since been limited to occasional outbursts of localized clashes and continued high civilian fatalities from mines and unexploded ordinances. In late 2023, the Ansarallah Government of Yemen began targeting commercial vessels in the Red Sea and Gulf of Aden as part of its support for Hamas against Israel during the war in Gaza. This sparked an interstate conflict with United Kingdom and United States in December 2023, as they launched airstrikes on Yemen. In mid-March 2025, the United States greatly stepped up these airstrikes, killing nearly 800 people over the next month and a half, before announcing a ceasefire. Immediately following on the U.S. campaign, Israel launched its own attacks. with the express aim of dismantling Ansarallah's leadership. As Ansarallah functions as the Government of Yemen in UCDP's data, due to their control of the capital, this became the second active interstate conflict involving Yemen during 2025. In August, Israeli airstrikes killed several top officials, including the Prime Minister and Chief of Staff.

In November 2025, the STC, a United Arab Emirate (UAE)-backed separatist groups that had been an important part of the Forces of the Presidential Leadership Council (PLC), rebelled, and launched a military campaign which captured Hadramawt and Mahra governorates from the PLC. By the end of December, STC held essentially all areas that had constituted South Yemen prior to unification, while the PLC (the internationally recognized government of Yemen) only had a few isolated holdouts of actual control in Yemen, mainly in Marib and Taiz. On 2 January, STC went as far as to declare the independence of the 'State of South Arabia'. The rapid expansion of STC on Saudi Arabia's border sparked a strong response, with Saudi Arabia launching airstrikes in support of PLC forces in December and January, as well as warning strikes directly on UAE bases in Yemen. Alongside political pressure that caused severe defections from the STC, Saudi Arabia successfully instigated the rapid collapse of the STC, which in a month went from controlling half of Yemen to being little more than an rural insurgent group in Dali and Lahij governorates. The splintering of STC from the PLC also reignited the South Yemen conflict, latent since 1994, as clashes between STC and Ansarallah government forces continued along shared frontlines. Prior to the STC's splinter, such violence would have been considered part of the conflict over government between the Ansarallah Government of Yemen and Forces of the Presidential Leadership Council.

Small-scale non-state violence between the Forces of the Presidential Leadership Council and AQAP (al-Qaida in the Arabian Peninsula), as well as between AQAP and STC, continued in southern Yemen during 2025.

History of North Yemen and unification with the South

In the 19th century, the southern part of Yemen became a British colony whereas the northern part of country came under the rule of the Ottoman Empire. Ottoman rule of Northern Yemen was always weak, being consistently challenged by the Zaydi Shiite tribes from the northwestern highlands under the command of their Hamididdini Imams. Upon the end of the First World War, and the subsequent collapse of the Ottoman Empire, North Yemen gained independence, while South Yemen remained under British administration until 1967. North Yemen, with its meager resources and reputation for being ungovernable, retained its independence at a time when European Empires dominated the region, but remained deeply impoverished and underdeveloped.

The history of independent North Yemen was marked by several violent power struggles. In 1918, Imam Yahya Hamididdin al-Mutawwakil took over power from the Ottomans. Whilst Imam Yahya was initially popular, his authoritarian theocratic rule caused dissatisfaction among some portions of the population, which culminated in his assassination by reformers in 1948. A coalition of Zaydi tribes rallied to support Imam Yahya’s eldest son Ahmed as the new Imam. Imam Ahmad thereby succeeded in overthrowing the short-lived reformist government set up by the assassins in a short intrastate conflict. A coup in 1955 briefly deposed Imam Ahmad, who rapidly managed to retake power, however.

Both Imam Yahya and Imam Ahmad isolated North Yemen from the outside world, rejecting most outside interference and investments into the Imamate. Faced with growing pressure from reformists and pro-Arabists, Imam Ahmad broke Yemen’s isolation by joining Egyptian President Gamal Abdel Nasser’s pan-Arabic confederation, the United Arab States (a much looser union than the contemporary United Arab Republic between Egypt and Syria), 1958-1961.

When Imam Ahmed died in 1962, his son Muhammad al-Badr became Imam, but Egyptian-trained Nasserist officers ousted him within a week. An intrastate conflict ensued between the Royalists – the supporters of the Imam, primarily made up of Zaydi tribesmen – and the new government that had established a republic in North Yemen. The North Yemen republican government was supported by Nasser’s Egypt, which became increasingly bogged down with large military forces in the costly and protracted civil war. The republican coup was perceived threatening by other Arab monarchies, particularly Saudi Arabia and Jordan, which provided support for the Royalists. The rapprochement of republican and monarchist Arab states after the Arab defeat in the Six Day War to Israel in 1967 led to Egypt withdrawing its forces from Yemen, and Saudi Arabia to end its support for the Royalists and recognizing the republican government. After Saudi Arabia abandoned its support most Royalist leaders reached a reconciliation with the republican government, whereas Imam al-Badr went into exile.

The end to the civil war was followed by a rapid series of coups and assassinations. The government of President Abdul Rahman al-Eryani, which achieved reconciliation with the Royalists, was overthrown by a military coup in 1974. The coup leader, Ibrahim al-Hamdi, who took over as president following the coup was thereafter assassinated in 1977. His successor, Ahmad al-Ghashmi, was assassinated only eight months later, leading to Ali Abdullah Saleh taking power in 1978. Saleh would remain the President of first North Yemen and then the unified Yemen for over 30 years.

In colonial South Yemen, pro-independence movements emerged in the 1960s. The NLF (National Liberation Front) and the FLOSY (Front for the Liberation of Southern Yemen) fought the British colonial power from 1964 to 1967. As a result of the conflict, the British rulers transferred the power to the most powerful of the groups, the NLF, and granted independence to South Yemen in 1967. The NLF was reformed into the Yemeni Socialist Party (YSP) in 1978.

The relations between independent socialist South Yemen and western-oriented North Yemen were strained at times and common border conflicts occurred in 1972 and 1978-1979. South Yemen also financially supported an opposition coalition in North Yemen, the leftist National Democratic Front (NDF), which fought the government in an intrastate conflict from 1980-1982.

In South Yemen, a faction of the ruling Yemenite Socialist Party, later called the Zumra, engaged in a short intrastate conflict against the Yemeni Socialist Party - Abdul Fattah Ismail faction (YSP – AFI) in 1986, after President Ali Nasser Mohammed had attempted to assassinate several rivals within the YSP. Despite lasting only eleven days, the conflict was fought with extreme ferocity and would have far reaching consequences by solidifying intra-southern divisions. Both factions represented different parts of South Yemeni society, and was dominated by different tribal factions. The YSP – Abdul Fattah Ismail faction, often known as the Toghma (meaning 'ruling clique'), emerged victorious, though Ismail himself died during the conflict. Instead, Ali Salem al-Beidh rose to power. Al-Beidh paved the way for the peaceful unification with North Yemen in 1990, with al-Beidh becoming vice president of the unified state. Many of the survivors of the opposing faction, often derogatorily called the Zumra faction, had fled to the North, and was integrated into the North Yemen army as the Unity Brigades prior to unification.

Governance by dancing on the heads of snakes

Despite being viewed by his Saudi and US backers as a guarantor of stability in Yemen, the 33-year dictatorship of Ali Abdullah Saleh that began in 1978 was filled with conflicts. The authoritarian president himself described ruling Yemen as “dancing on the heads of snakes”, in reference to the many uprisings, civil wars and tribal feuds he had to navigate to stay at the helm of the nation. He largely succeeded in this by playing of various factions against each other, and by building close ties with many highland tribes through an extensive patronage network. His most important ally in this was Sheikh Abdullah Bin Hussein Al-Ahmar, sometimes called the sheikh of sheikhs for his influential role in mediating Saleh's relationship with the tribes of Yemen. Al-Ahmar was up until his death in 2007 the sheikh of the powerful Hashid tribal confederation, Saleh's own tribe, and the leader of the Islah party.

Since the unification of North and South Yemen in 1990, southern separatism has remained a threat to the unified state. Four years after unification, a secessionist movement, the Democratic Republic of Yemen, unsuccessfully attempted to re-establish an independent South Yemen. The uprising was led by the last leader of South Yemen and thereafter vice president of the united Yemen, Ali Salem al-Beidh. After a short war, the movement was defeated by the Government of Yemen in July 1994. The 1994 breakaway attempt was defeated in part by the losers of 1986, the Zumra survivors that became the Unity Brigades. Leading the return of the Zumra was Abdrabuh Mansur Hadi, who would later become vice-president under Saleh and president of Yemen after Saleh was deposed. Power in southern Yemen was thereafter monopolized by the so-called Zumra, who made sure to keep the former Toghma affiliates out of positions of power and thus outside of the state-sponsored patronage network.

Southern separatism has occasionally flared since, often driven by the marginalized sections of South Yemeni society that aligned first with YSP – AFI in 1986 and with the Democratic Republic of Yemen in 1994. For instance, the loosely organized Southern Movement was engaged in occasional clashes with government forces since 2009, and supporters of the movement coalesced into the Southern Transitional Council (STC) in 2017. STC has mainly fought as part of Forces of the Presidential Leadership Council (pre-2022 called Forces of Hadi), and only became active in the South Yemen conflict after STC splintered from the Presidential Leadership Council in 2025. By that time, it had become one of the most powerful factions in Yemen, controlling almost all territories that historically had been part of South Yemen. The STC has repeatedly been engaged in non-state violence with the Forces of the Presidential Leadership Council since 2018.

The main challenge to the government of unified Yemen came from the Zaydi Shiite tribes of Yemen’s northwestern highlands. The Zaydi tribes, in particular the old sāda (sing. Sayyid) elite, had been the dominant political force in North Yemen for most of its history, with the Zaydi Imams being the rulers of North Yemen from its independence in 1918 until the republican coup in 1962, and prior to this ruling parts of or all of Yemen in various capacities with few interruptions since the 9th century. A Zaydi revivalist movement called Ansarallah (Supporters of God, originally called the Believing Youth) was formed in 1992 by Hussein Badr al Din al Houthi. It aimed to end the perceived the persecution of sāda and the growing influence of Sunni Islam in the Zaydi heartland, with evangelizing groups such as the Salafist Dar al-Hadith having been sponsored by the Saleh regime. Due to the prominence of members of the Sayyidi al-Houthi family, Ansarallah were often referred to as Houthis by its opponents.

Clashes erupted in 2004 after the attempted arrest of Ansarallah’s leader, and several rounds of conflicts known as the 'Saada Wars' were fought 2004-2010. The conflict was originally fought over issues not related to government or territory, with Ansarallah repeatedly denying that they intended to overthrow the government, and therefore not included in UCDP data. In June 2008, during the fifth phase of the conflict, Ansarallah made apparent their intention to use violence to remove Saleh based on him being an agent of Israel and the United States, thus activating the conflict over government. The fifth conflict ended only weeks later in a ceasefire agreement with the government, after a brutal conflict in which around 1,000 government soldiers are believed to have been killed earlier in the year. A new round of fighting erupted in August 2009, killing at least some 1,300 people during the year, and not ending until the following year. Between November 2009 and February 2010, Ansarallah also clashed extensively with Saudi Arabia. Ansarallah crossed the border into Saudi Arabia in November, ostensibly in punishment over Saudi Arabia's support for the Yemeni government. Due to the lack of a valid incompatibility this violence is excluded.

In 2009, al-Qaida in the Arabian Peninsula (AQAP) was formed with the intent of turning Yemen into an Islamic Emirate and begun an armed conflict against the Government of Yemen. By 2011, AQAP had become one of the most active and dangerous branches of the al-Qaida network, mainly active in fighting government forces in Abyan governorate in southern Yemen. The Government of United States of America perceived the threat as serious enough to give the Government of Yemen secondary warring support, conducting airstrikes in Yemen against AQAP since 2009.

President Ali Abdullah Saleh was ousted during the massive popular protests of the Arab Spring, which spread to Yemen in January 2011. The violent response by the government triggered mass defections among the regime's supports in the military and among the tribes, and also caused parts of the opposition to take up arms. Government forces fought dissident military units in the Free Yemeni Army, and armed opposition members of Islah and the Alliance of Yemeni Tribes during the year, in addition to the already ongoing conflicts with Ansarallah and AQAP.

During this period of instability, as security forces turned on each other and loyalist forces concentrated on the capital to protect the regime, the governments effective control of the country diminished as the various armed groups, most notably Ansarallah and AQAP, greatly expanded their territorial control. Several of these groups also fought each other, as they competed over territorial control in the power-vacuum caused by the collapse in government authority. In November, Saleh agreed to transition power to his vice president since 1994, Abdrabbuh Mansur Hadi. Elections were held in February 2012, with Hadi as the only candidate running. Hadi was to serve as the interim president during for two years, after which free elections were supposed to be held. However, in January 2014, a conference primarily consisting of Hadi’s allies, after Ansarallah had withdrawn, extended his term as president, over the protests of Ansarallah, which declared the move illegitimate.

Civil war

On 9 March 2014, after Hadi’s original interim term had expired, Ansarallah demanded the government resign, and clashes soon flared up. Central government authority had greatly weakened in many areas at this point, and Ansarallah had already gained control over large parts of northwestern Yemen.

During the early spring of 2014, Ansarallah advanced south from the Sadah governorate to Amran governorate and also towards the capital Sanaa. The group seized control of Amran town and the governorate with the same name in July. Resistance from government and tribal forces was subdued, which is often credited to the alliance between the former president Saleh and his network, centered on the General People's Congress (GPC) party, and Ansarallah. Saleh allied with his former enemies in Ansarallah against his own former vice-president and successor to the presidency, Hadi, in an apparent bid to re-secure his influence in Yemen.

On 21 September, Ansarallah took control of most of the capital. As the group advanced, many units of the security forces and governmental agencies capitulated, including the Interior Ministry which ordered its personnel to cooperate with Ansarallah. The resistance to the Ansarallah advance into the capital was spearheaded by government forces loyal to General Ali Muhsin al-Ahmar, who was a close ally of the Muslim Brotherhood (Ikhwan)-aligned Islah party and had led the Free Yemeni Army during the overthrow of Saleh. These forces reportedly acted on their own accord, rather than on the president’s order, resulting in a relatively limited defense of the capital.

The takeover of most of the capital resulted in a peace agreement, known as the “Peace and National Partnership Agreement”. Hadi was to appoint a new government was formed with compromise candidate Khalid Bahah as prime minister. The agreement pushed the Islah party out of power, and many of its leaders and allies, including General Ali Muhsin al-Ahmar, withdrew to the south. Despite the fulfillment of Ansarallah’s demands, the group kept its troops in the capital and exerted heavy influence on government policies. The group unilaterally appointed regional governors and halted the appointment of a new army chief of staff. After the September agreement, Ansarallah was able to greatly expanded its own territorial control, with the government too paralyzed to counter it. Heavy fighting with AQAP erupted in October as Ansarallah entered Bayda governorate. By late November fighting died down with Ansarallah in control of most of the governorate.

In 2015, the violence in Yemen escalated drastically. Ansarallah, in alliance with forces loyal to former President Saleh, ousted the government led by President Hadi and took full control over the capital on 20 January. According to UCDP definitions, Ansarallah was then seen as the Government of Yemen. Hadi was thereafter put under house arrest and was forced to resign on 22 January. After having managed to flee to Aden, Hadi retracted his resignation on 21 February and resumed the position as president. While his government was the internationally recognized one, Forces of Hadi was a non-state actor in UCDP data as the Ansarallah government controlled the capital.

Fighting rapidly followed Hadi southward, reaching Aden in March, as the Ansarallah Government of Yemen tried to put a quick end to resistance to their rule. Various factions and militias opposed to Ansarallah rallied behind Hadi, bolstering his forces primarily in southern Yemen. As pressure mounted on Hadi, and it appeared likely that the Iran-backed Shiite Ansarallah movement would come to rule Yemen, Saudi Arabia led a coalition of Arab states to militarily intervene to reinstall Hadi. The coalition consisted of Saudi Arabia, Egypt, Morocco, Jordan, Sudan, UAE, Kuwait, Qatar and Bahrain, and largely aimed at limiting Iranian influence in the region.

The Ansarallah government forces were forced to retreat from Aden under heavy pressure from coalition airstrikes in late July 2015, after four months of heavy fighting in the interim capital. The defeat of Ansarallah in Aden hindered the collapse of the Forces of Hadi and prolonged the conflict. The Forces of Hadi thereafter consolidated its forces and expanded its coalition with the help of financial aid from its Gulf allies.

In the security vacuum that emerged after the Hadi government was overthrown in 2015, AQAP managed to capture considerable territory in eastern Yemen. Most notably, they captured the town of Mukalla, which became the capital of their Emirate in Yemen. AQAP thereafter mainly fought in the non-state conflict against the Forces of Hadi. Mukalla was recaptured by the Forces of Hadi in April 2016, just over a year after it was taken by AQAP. AQAP entered a state of slow decline after, suffering from further territorial losses, leadership losses to airstrikes by the USA and defections to IS. The Forces of Hadi received secondary warring support from USA and UAE in the non-state conflict against AQAP. The Ansarallah Government of Yemen has also occasionally fought AQAP, though the rate of fighting has steadily declined as AQAP weakened and lost ground.

A territorial conflict between the Government of Yemen and IS became active in 2015, though fighting since has been sporadic. IS has mainly fought in non-state conflicts, specifically Forces of Hadi - IS and AQAP - IS. The non-state conflicts Forces of Hadi - AQAP and Forces of Hadi - IS both peaked in 2016, as extensive battles were fought for control of the interim capital, Aden, and Forces of Hadi recaptured Mukalla from AQAP. In 2020, IS lost its last stronghold in Yemen, the al-Qayfa area in Bayda governorate, to the Ansarallah Government of Yemen, and has not been active in any conflict in Yemen since.

The conflict over government between the Government of Yemen and Forces of Hadi continued unabated in 2016-2018 (for a more detailed account see Yemen: government). The Saudi-led coalition continued to carry out airstrikes against the Government of Yemen, in support of Forces of Hadi. In 2017, a new actor became active in the conflict over government in Yemen as relations broke down between the Ansarallah government and their allies in the General People's Congress (GPC), the umbrella party of the various military forces loyal to former President Saleh. Hundreds died in several days of intense fighting in and around the capital Sanaa. Saleh himself died in the fighting on 5 December 2017, causing the GPC to splinter and the remainder of its forces to scatter. Part of the GPC remained loyal to Saleh's relatives, Ahmad Saleh and Tariq Saleh. The leading pro-Saleh faction organized military forces under the banner of the Yemeni National Resistance Forces (NRF), led by Tariq Saleh, and later participated as part of the Forces of Hadi. Those that remained in Ansarallah-controlled areas were reorganized as a pro-Houthi branch of the party under the leadership of Sadeq Amin Abu Rass.

The conflict in Yemen has taken an enormous toll on the civilian population and the International Committee of the Red Cross (ICRC) described Yemen as "the world's single largest humanitarian crisis" in 2018, with over 20 million people in need of aid. The situation has continued to deteriorate since, even as some relief was offered by the signing of the country-wide ceasefire in 2022.

The Stockholm Agreement and localized de-escalation

The parties met for peace negotiations in Sweden on 6-13 December 2018, which ended in the signing of the Stockholm Agreement, which came into effect on 18 December. The agreement included a localized ceasefire around Hudaydah city, mostly due to international pressure, stemming from concern over the humanitarian impact fighting in one of Yemen's largest cities would have. While some steps to implement the agreement was taken, such as an exchange of prisoners, other parts of the agreement stalled. A few minor clashes occurred around the city, but the ceasefire and redeployment of troops away from Hudaydah dramatically decreased the violence in one of the hardest hit areas in Yemen. As a result, the number of recorded battle-related deaths in Yemen decreased markedly in 2019 compared to 2018. Despite the de-escalation, clashes continued throughout the year in other parts of Yemen, and the civilian impact of the conflict remained disastrous.

Even as the conflict over government calmed in 2019, the divisions within the Forces of Hadi flared up. The UAE-backed southern separatist movement Southern Transitional Council (STC) broke out of the pro-Hadi forces and seized the interim capital Aden in August as the intended capital for a reborn South Yemen state (see Forces of Hadi – STC). Despite a relatively fast reconciliation, resulting in STC forces yet again joining the Forces of Hadi through a power-sharing agreement in October, the separatist forces retained de facto control of the interim capital, with pro-Hadi officials mainly operating from Saudi Arabia. Relations remained tense, however, and renewed bouts of even more intense fighting erupted in April 2020.

Renewed escalation: 2020-2021

The state-based conflict over government between the Ansarallah Government of Yemen and Forces of Hadi escalated again in 2020, as fighting moved eastwards from Hudaydah towards the last major northern areas controlled by the Forces of Hadi in al-Jawf and Marib governorates. The Ansarallah government made some territorial gains in these areas, advancing through al-Jawf, Sanaa's Nihm district and making minor gains in northern and western Marib. They captured Hazm town in March and most of the rest of al-Jawf by late April. In November, the strategically important Mas Camp in Marib’s Madghil district was seized, which opened up the northwestern approach towards Marib town. Following this success, they launched a massive offensive towards Marib town in February 2021, resulting in some of the heaviest fighting of the conflict. In most other areas the frontlines remained relatively stable.

At first, the Ansarallah Government of Yemen made only incremental progress, whilst suffering massive casualties, to a large extent due to Saudi airstrikes. The momentum shifted decisively in the favor of Ansarallah during the summer and fall of 2021. In September, all of Al Bayda governorate fell to Ansarallah. Already in 2020, they had made gains in the al-Qayfa area in Bayda governorate, where they inflicted significant defeats upon the IS and AQAP forces residing there. Using Al Bayda as a launching pad, Ansarallah captured five districts in the governorates of Marib and Shabwa between September and October, thereby cutting off the southern supply route to Marib town for the Forces of Hadi and nearly encircling the town in the process. The gains came at a heavy cost, with Ansarallah admitting to have lost almost 15,000 fighters just between June and November in Marib and its surroundings, making 2021 the most deadly year of the conflict.

Despite speculation during the autumn that Marib soon would fall, the offensive stalled for the rest of the year, and was even partially reversed as a Forces of Hadi counter-offensive through Shabwah and into southern Marib started in late December. The counter-offensive was conducted mainly by the Giants Brigades, which until recently had been deployed along the relatively calm ceasefire lines in Hudaydah governorate.

On 9 November, the UAE-backed National Resistance Forces (NRF), a loose coalition consisting of the Guardians of the Republic, the Tihama Resistance and the Giants Brigades, which has been fighting as part of the Forces of Hadi, suddenly began withdrawing from much of southern Hudaydah governorate. These forces are some of the best-equipped and trained forces in the coalition supporting Hadi, having been trained and equipped by the UAE. They have, however, seen relatively little use since the Stockholm Agreement in 2018, as they remained guarding a relatively calm ceasefire line as fighting moved elsewhere. In November, they abandoned the districts of al-Hawk, al-Duraihimi, al-Tuhaita and Beit al-Faqih to the Ansarallah government, thus shaking up the military situation along the west coast. This resulted in some of the most intensive clashes in Hudaydah governorate since the signing of the Stockholm Agreement, though violence no longer threatened the major urban center of the city of Hudaydah. The withdrawal was part of a redeployment of the Giants Brigades from the static Hudaydah frontlines to initiate a counter-offensive through Shabwah and into southern Marib starting in late December.

Hadi resigns and a country-wide ceasefire is signed

On 7 April 2022, the internationally recognized President of Yemen, Abdrabuh Mansur Hadi, resigned and was replaced by an eight-man Presidential Leadership Council (PLC), consisting of the major warlords in the anti-Ansarallah camp. The coalition that had supported Hadi as president was thus renamed the Forces of the Presidential Leadership Council. The PLC was chaired by Rashad al-Alimi, and its members represented the major military factions fighting the Ansarallah Government of Yemen. It comprised several members from Islah, as well as the leader of both the Guardians of the Republic and the NRF, Tariq Saleh, the leader of Southern Transitional Council (STC), Aidarus al-Zoubaidi, and the leader of the Giants Brigades, Abdulrahman Abu Zara'a Al Muharrami. STC consolidate its hold of southern Yemen and its influence in the PLC in 2023, by merging with the Giants Brigades and recruiting several influential figures from the eastern governorates, including the PLC member and former governor of Hadramaut, Faraj Salmin Al-Bahsani. By the end of 2023, three of the eight members of the Presidential Leadership Council were members of the STC, making the southern separatist movement the single biggest block within the leadership of the anti-Ansarallah coalition. A fourth member, the NRF's Tariq Saleh, also belonged to UAE-backed factions, while the remainder of the council had closer ties to Saudi Arabia.

The move to appoint the PLC was meant to better the coalitions bargaining position during the “transitional phase” between entry of the ceasefire on 2 April and the supposed election of a new president after the signing of a peace treaty. Whilst the UN-sponsored talks held with the Ansarallah government resulted in the ceasefire being prolonged several times, and the easing of restrictions for the movement of goods and people in Yemen, they reportedly remained limited to managing the conflict, rather than resolving it. Throughout the ceasefire, violence between the parties remained at relatively low levels, with around three-quarters of the fatalities reported in fighting between Ansarallah government and the Forces of the Presidential Leadership Council in 2022 occurring prior to the signing of the truce on 2 April. The ceasefire expired on 2 October 2022, amidst disagreement over the responsibility for the payment of public officials’ salaries in areas controlled by Ansarallah.

Violence did not immediately escalate, as renewed talks were soon initiated between the Ansarallah government and Saudi Arabia, the main external backer of the PLC. These talks continued throughout 2023, with the result that an informal ceasefire was maintained along the frontlines throughout the year. With neither side willing to escalate tensions to the point that it threatened the talks with Saudi Arabia, even amidst significant worry in the PLC camp that these talks do not necessarily represent their interests, violence was limited to the occasional outbursts of localized clashes and continued high civilian fatalities from mines and unexploded ordinances. Ansarallah appeared to have hoped to convince Saudi Arabia to withdraw from Yemen, leaving them to deal with the PLC from a position of strength. Saudi Arabia on the other hand appeared to have been seeking an exit from what had become a costly Yemeni quagmire; seeking a solution that both secures its southern border and allows it to maintain some degree of influence over Yemeni affairs. Saudi Arabia has expressed particular concern over the increasingly close ties between Ansarallah and Iran, which has deepened considerably during the war.

The Ansarallah-Saudi talks were put on hold in 2024 amid a US-led campaign of airstrikes (see below) to degrade the threat from Yemen on international shipping. Despite the end to the talks, violence continued at relatively low levels. Many of the key factions of the PLC, in particular the NRF and the large Hashid and Bakil tribal confederations, were openly pushing the PLC towards restarting the war by early 2025, however, perceiving an opportunity given the degradation of Ansarallah’s capabilities from US airstrikes and the weakening of its allies in the Axis of Resistance, as exemplified by the collapse of the Iran-backed Government of Syria in December 2024. Despite this, fighting continued to decrease during 2025.

Interstate conflicts against United Kingdom, United States and against Israel

The close ties between Ansarallah and Iran became particularly evident after the crisis in Gaza developed in October 2023, leading to Ansarallah coming out in full support of the Iranian-led ‘Axis of Resistance’ by attacking international shipping, supposedly connected to Israel, in the Red Sea, Bab al-Mandeb straits and Gulf of Aden, as well as participating as a secondary warring party to Hamas by firing missiles on Israel and being bombed in return. Ansarallah claimed to have the right to “sovereign decision-making” in blocking access to shipping by its enemies, in this case Israel, in the Bab al-Mandeb Straits, Gulf of Aden and southern Red Sea, contradicting the status of these seas as international waters. The attacks on international shipping sparked the formation of ‘Operation Prosperity Guardian’ in December 2023, a US-led coalition of states that sent combat vessels, including aircraft carriers from the UK and USA, to protect shipping in the disputed seas. This resulted in an United Kingdom, United States - Yemen interstate conflict, which has seen both clashes between the navy of the Ansarallah Government of Yemen and coalition vessels, and American-British missile- and airstrikes on Ansarallah targets within Yemen. The conflict did not reach the threshold of 25 deaths for inclusion in 2023, but did so in the early months of 2024. The US-UK strikes on Yemen continued throughout 2024, focusing on degrading the missile threat from Yemen. The United States escalated the dramatically in March of 2025, launching a renewed campaign of airstrikes which killed nearly 800 people over the next month and a half, as the newly re-elected US President Donald Trump sought to put pressure on Iran by weakening its allies ahead of planned negotiations on the Iranian nuclear program. While most of the dead were likely members of Ansarallah, several strikes caused mass civilian casualties, notably a strike on a fuel port in April which killed around 90 civilians, followed by a strike on a migrant detention centre that killed over 60 civilians. In early May, a ceasefire agreement was suddenly announced, in which the United States would end its attacks in exchange for an end to Yemeni targeting of vessels in the Red Sea.

Immediately following on the U.S. campaign, Israel launched its own attacks with the express aim of dismantling Ansarallah's leadership. As Ansarallah functions as the Government of Yemen in UCDP's data, due to their control of the capital, this became the second active interstate conflict involving Yemen during 2025. After the strikes in May, Israel launched a second round of strikes in August and September. On 28 August, Israeli airstrikes killed around a dozen ministers of the Ansarallah government, including the Prime Minister and Chief of Staff. With the signing of a ceasefire between Hamas and Israel in October, the Yemeni strikes on vessels in the Red Sea and on Israel ended, and Israeli airstrikes on Yemen came to a halt.

Complex relations: factionalism and non-state fighting in Yemen’s civil war

The Forces of the Presidential Leadership Council was a broad coalition with diverse aims, that mainly had agreed to recognize the Hadi administration, and later the Presidential Leadership Council, as a way of opposing Ansarallah. One of its most ill-fitting partners is the STC, a which sought to restore the independence of South Yemen. STC has increased its influence in southern Yemen through several outbreaks of conflict against the other factions in the Forces of Presidential Leadership Council.

Fighting between the STC and the Forces of Hadi broke out in Aden town in late January 2018, after the STC had demanded the withdrawal of security forces loyal to Hadi from the city. STC leader Aidarous al-Zubaid declared his forces had "begun the process of overthrowing” Hadi’s rule over South Yemen. Only days later, however, they affirmed their support for the Hadi's government and its war with the Houthi-government, thus becoming part of the Forces of Hadi. A new bout of fighting broke out on 7 August 2019, resulting in STC capturing Aden town, the interim capital of the Hadi government, forcing the Hadi's government into exile, mainly in Saudi Arabia. On 25 October 2019, they became part of the Forces of Hadi through a power-sharing agreement. The agreement broke down in early 2020, however. On 26 April 2020, the STC broke with the Hadi government and announced it would establish self-rule in areas under its control. Widespread clashes broke out between the parties soon thereafter, mainly concentrated to Abyan governorate in southern Yemen. Fighting finally ended after a new power-sharing agreement was reached after international mediation attempts on 10 December, resulting in the STC yet again joining the Forces of Hadi, and some pro-Hadi officials returning to Aden for the first time since 2019.

A constant source of friction within the PLC-coalition has been between Islah, a Muslim Brotherhood-aligned party that was a linchpin in the pro-Hadi coalition early on, and the UAE and its local allies, in particular STC and the Giants Brigade. Over time, Islah’s influence has weakened, especially after Hadi and his Islah-aligned vice president, Ali Muhsin al-Ahmar, was replaced with the PLC in April 2022. Without strong support from the Hadi administration, Islah suffered a string of defeats in July and August 2022, as the UAE-backed Giants Brigades and STC violently drove Islah out of Shabwah and removed the Islah-aligned governor of Hadramawt.

In late-November 2025, the STC rebelled again, by launching a military campaign to capture Hadramawt and Mahra governorates from the PLC. The first target of the operation was the Hadramawt Tribal Alliance (HTA), a Saudi-backed outfit that has sought to unite Hadrami tribes behind a vision of self-governance within a unified Yemen, functioning as a counter to the STC's vision of southern separatism that had been making inroads in Hadrami society. Backed by UAE airstrikes, STC captured several key areas from HTA, before turning its attention directly on the PLC forces that held Sayun city. After a week of fighting, PLC forces withdrew from the city and most of the governorate. The STC simultaneously advanced into Mahra governorate, Yemen's easternmost province, capturing it without a fight.

On 26 December, Saudi Arabia warned the STC to withdraw from its newly captured territory, a day after it had launched airstrikes on advancing STC forces in support of both HTA and PLC, saying the seizure of the provinces bordering Saudi Arabia constituted threat to their national security. On the 30th, Saudi Arabia also launched strikes targeting a military base belonging to the UAE, while warning them about supporting the STC, while the president of the PLC ordered all UAE forces to withdraw from Yemen, overriding opposition from the half of the leadership council belonging to UAE-backed factions. While the UAE formally acquiesced to the request to withdraw, the STC refused to withdraw from its captured territory. On 2 January, the STC, having finally achieved its goal to control all the territories of South Yemen prior to unification, went as far as to declare the independence of the 'State of South Arabia'. This left the PLC, which is broadly recognized as the legitimate government of Yemen, severely weakened with only small pockets of Yemeni territory under its control.

The Saudi intervention, combined with highly active Saudi diplomatic pressure on factions aligned with the UAE and STC, caused the movement the rapidly fracture while at the height of its territorial control. On 3 January, political and security heavy weights that had held Shabwah and Abyan for the STC defected to the PLC, followed over the next few days by the defection of the STC's Hadrami Elite Forces and the powerful Giants Brigades. Several prominent STC figures, as well as other UAE-backed leaders such as the NRF's Tariq Saleh, were allegedly placed under house arrest during visits to negotiate in Saudi Arabia until they had signed agreements with Saudi Arabia. As a result, the STC leaders that went to Saudi Arabia announced the groups dissolution on the 9th, which was firmly rejected by STC leaders in Yemen and the UAE. The defections appeared to take the fight out of STC, however, as by 7 January the Giants Brigades had assumed control of the supposed capital of their new state, Aden, on behalf of the PLC and the STC leader was reported to have fled to the UAE. Saudi Arabia successfully instigated the rapid collapse of the STC, which in a month went from controlling half of Yemen to being little more than a rural insurgent group in Dali and Lahij governorates.

Both AQAP and IS had been severely weakened in recent years, and former and current members of the groups reportedly fought alongside the Forces of the PLC against the Ansarallah government, especially during the Marib offensive in 2021-2022. Small-scale fighting between the Forces of the Presidential Leadership Council and AQAP has continued, though at a much diminished pace from when AQAP was at its prime in 2016. Fighting picked up again in 2022, as the former Islah-aligned security forces in Shabwah governorate was replaced by STC-aligned units, which subsequently launched a security campaign to drive AQAP from Shabwah and Abyan, resulting in fierce fighting and regular ambushes. The next few years saw a decrease in fighting as the STC strengthened its hold of contested areas, though AQAP launched a series of deadly attacks on STC forces after they had broken with the PLC at the end of 2025. AQAP was last active in the conflict against the Ansarallah government in 2018. IS was last active in the statebased conflict in 2020, and in the non-state conflict with the Forces of the PLC in 2018.

International involvement

Most members of the coalition that backed the Forces of Hadi, which originally consisted of Saudi Arabia, Egypt, Morocco, Jordan, Sudan, UAE, Kuwait, Qatar and Bahrain, have gradually withdrawn from Yemen. Eritrea, whilst not a member of the coalition, sent soldiers embedded under the UAE contingent. As of 2025, only Saudi Arabia, Bahrain and UAE had soldiers fighting within the country.

Saudi Arabia has continued to maintain a considerable presence in Yemen, and have been an extremely important supporter of the Forces of the Presidential Leadership Council due to their reliance on Saudi airstrikes. Saudi Arabia has primarily backed the central authority of the PLC, first President Hadi and later PLC-chair Rashad al-Alimi, as well as the Islah and an array of tribal factions. Their forces have been backed by a small contingent from Bahrain, in particular along a buffer zone Saudi Arabia has set up inside Yemen along parts of its border.

UAE has been the other major backer of the PLC, though it has primarily supported rival factions to those backed by Saudi Arabia. UAE claimed to have finished its withdrawal of active fighting forces in February 2020, but reportedly continued to conduct occasional drone strikes to protect its interest in the country. It also continued to maintain some military bases, and has trained and financed several ostensibly pro-Hadi factions, most notably the STC, the National Resistance Forces (NRF) and Giants Brigades. As the pro-Hadi forces looked set to loose Marib in 2021, the UAE again stepped up its support for the coalition as its close allies in the Giants Brigade took a more proactive role in the fighting in eastern Yemen. After the STC uprising against the PLC in late 2025, Saudi Arabia launched strikes targeting a military base belonging to the UAE, while warning them about supporting the STC. In conjuncture with this the president of the PLC ordered all UAE forces to withdraw from Yemen, overriding opposition from the half of the leadership council belonging to UAE-backed factions. The UAE formally acquiesced to the request to withdraw, potentially ending its decade-long involvement in Yemen.

Sudan drastically reduced the number of troops in Yemen in late 2019, from 15,000 to 5,000. The forces from Sudan remaining in Yemen were aligned with the Rapid Support Forces (RSF), meaning that Sudan's formal secondary warring support ended as the civil war broke out in Sudan between RSF and the government in 2023, despite a small Sudanese presence remaining in Yemen. The RSF participation in Yemen has been financed by the UAE.

The United States has provided support through airstrikes for the Forces of PLC against AQAP and against IS. US attacks on Ansarallah since 2023 has been related to the Ansarallah blockade of the Red Sea and is coded to the United Kingdom, United States - Yemen conflict.

There have also been allegations of officers from the Iranian Revolutionary Guard Corps (IRGC) and Hezbollah commanding and training the forces of the Houthi government, though their participation in direct combat roles remained unconfirmed and denied by Iran. Whatever the truth of direct participation of Iran in the conflict, the Ansarallah government has received increasing amounts of material and political support from Iran during the conflict. Despite this, Ansarallah has never been nearly as close to Iran, or as dependent on Iranian support, as many other so-called Iranian proxies, such as Hezbollah in Lebanon or many of the factions within the Iraqi government’s Popular Mobilization Forces.