Islamic State in Yemen

The Islamic State in Yemen (ISY) is the actor that represents the Yemeni province of the global caliphate claimed by the self-styled Islamic State (IS). IS aspires to replace ‘apostate’ Islamic regimes with ones inspired by ‘true’ Islamic values and it aims to establish local territorial control.¹ In Yemen, the Sunni Islamist rebel group was established in November 2014. ISY’s primary goal is to fight the Houthis, which are from the Zaydi branch of Shiite Islam. As of September 2023, ISY is estimated to have around 100 fighters, with safe havens reported in Marib and Shabwa governorates, and sleeper cells in Aden and al-Bayda.² Its activity has drastically decreased since 2021, with its role in Yemen’s conflict environment being at best marginal.

ISY Leadership

ISY does not have a known official leader. Its last known leader, Abu al-Walid al-Adani, was killed in a Houthi operation in al-Bayda governorate in August 2020.³ In August 2023, ISY pledged allegiance to the fifth caliph of the global IS franchise, who was announced a few days prior under the pseudonym of Abu Hafs al-Hashimi al-Qurashi.⁴ The true identity of this faceless leader, however, remains unknown. In May 2023, there were reports of ISY holding a meeting with its senior members in Shabwa governorate to work on a new organizational structure.⁵

Historical background

ISY was established in November 2014 after a number of defectors from the militant jihadist group al-Qaeda in the Arabian Peninsula (AQAP) pledged allegiance to the global caliphate declared by IS.⁶ ISY quickly adopted a radical stance along the Sunni-Shiite sectarian divide and attempted to position itself as spearheading the fight against the Houthis. In March 2015, it carried out simultaneous suicide bombings targeting two Shiite mosques in Sanaa city that led to a total of 142 reported fatalities. The group’s brutal tactics proved to be divisive within its own ranks, with mass defections taking place by the end of 2015 as some members denounced violations of Islamic law.⁷

Despite a number of high-profile attacks, ISY never took hold in Yemen. The group was largely seen as alien to Yemen’s social fabric due to the ruthless nature of its attacks and the fact that a sizable number of its fighters came from foreign countries.⁸ ISY also faced the challenge of finding a place within a jihadist environment already filled with the presence of well-rooted AQAP. Furthermore, if ISY initially gained traction following the successes of the IS in Iraq and Syria, the latter’s defeats later impaired the recruitment capacities of ISY. At its peak between 2016 and 2018, ISY was estimated to have no more than 500 fighters in its ranks.⁹ 

In 2018, the initial tacit pact of non-aggression between AQAP and ISY against their common Houthi enemy broke down, contributing to further depleting the group’s ranks between 2018 and 2020 (for more on clashes between AQAP and ISY, see this ACLED report). In August 2020, a Houthi offensive targeting ISY in its stronghold in al-Bayda governorate dealt the group its final blow, with the global IS spokesperson publicly admitting ISY’s defeat in October 2020.¹⁰ Since then, the group has been largely absent from Yemen’s conflict environment altogether, with ACLED recording only one violent event involving ISY over more than three years. However, there are reports of ISY trying to work on a new organizational structure. In May 2023, the group reportedly held a meeting with its senior members to that effect in Shabwa governorate.¹¹ 

In August 2023, ISY pledged allegiance to Abu Hafs al-Hashimi al-Qurashi, the fifth caliph of IS.¹² However, as of September 2023, this change in leadership has not tangibly affected ISY’s organization or agenda.

Timeline

• 2014
  • Nov. | The global IS leader accepts an oath of allegiance from Yemen leading to the creation of ISY
• 2015
  • Mar. | ISY militants conduct twin suicide bombings targeting Shiite mosques in Sanaa and reportedly kill 142
• 2017
  • Oct. | US drone strikes destroy ISY’s two main camps in al-Bayda governorate
• 2018-20 
  • Jul. 2018 – Feb. 2020 | ISY clash with AQAP in al-Bayda governorate
• 2020 
  • Aug. | Houthi forces kill the ISY leader in an operation in al-Bayda governorate
• 2023 
  • Aug. | ISY pledges allegiance to the Islamic State’s newly-announced fifth caliph Abu Hafs al-Hashimi al-Qurashi