SUMMARY
In 2015, the violence in Yemen escalated drastically. Ansarallah took control over the capital in January, making them the Government of Yemen according to UCDP definitions. While the government led by President Hadi was the internationally recognized one, due to the above-stated definitions, Forces of Hadi was seen as a non-state actor. Fighting with the Hadi government prior to 2015 and fighting against the Ansarallah government from 2015 is included in the conflict over government in Yemen. The Forces of Hadi (later renamed Forces of the Presidential Leadership Council) received secondary warring support from USA and UAE in the non-state conflict with AQAP, support which had begun while they were still the Government of Yemen.
In the security vacuum that emerged from the after the Hadi government was overthrown in 2015, AQAP managed to capture considerable territory in eastern Yemen. On 2 April 2015, a week after the start of the Saudi-led intervention, AQAP captured Mukalla, a major port city in the southeast of Yemen, from the Forces of Hadi. The goal of AQAP’s attack on Mukalla appears to have been more limited; staging a prison break to free AQAP’s emir in Abyan, Khaled Batarfi. With only a few hundred fighters, they managed to rapidly isolate and convince the various military bases, loyal to different factions that were mostly loosely aligned with the Forces of Hadi, in and around the city to surrender. No coordinated response to AQAP’s invasion was ever organized, allowing the outgunned AQAP fighters to achieve their foremost success in Yemen.
The conflict escalated in 2016, with heavy clashes particularly in the towns of Mukalla and Aden. Mukalla was recaptured by the Forces of Hadi in April 2016, just over a year after it was taken by AQAP. The force tasked with recapturing the city was spearheaded by local tribal fighters that had been trained and equipped by the UAE, and would later become the nucleus for the Hadrami Elite Forces. When the forces moved into the city on 24 April 2016, a deal for AQAP to withdraw from the city had been reached, and it was reported that the recapture was largely achieved without facing any resistance.
AQAP entered a state of slow decline thereafter, suffering from further territorial losses, leadership losses to airstrikes by the USA and defections to IS. Internal divisions, fighting with IS and pressure from US drone strikes has dismantled much of its capabilities since its heyday when it controlled an extensive emirate from the city of Mukalla. As the group weakened, former and current members of the group have been reported to have fought alongside the Forces of the Presidential Leadership Council against the Ansarallah government, especially during the 2021 Marib offensive.
2017 and 2018 saw less violence, but clashes, as well as US drone strikes, still took place throughout the year in mainly Abyan, al-Bayda, Hadramawt, Shabwah, and Lahi governorates. Violence in 2019 and 2020 were at even lower levels, and mainly consisted of US drone strikes. The trend of continuously decreasing activity by AQAP that has been ongoing since 2017 was broken in 2021. AQAP saw a slight uptick in activity during the year, in particular in Abyan governorate and, to a lesser extent, Hadramawt governorate. This trend continued in 2022, as the security situation in Abyan deteriorated due to internal strife within the Forces of the Presidential Leadership Council, through which PLC faction Southern Transitional Council (STC) conducted a series of coups against Islah-governed provinces in southern Yemen, thus taking over security in areas with a strong AQAP presence, leading to clashes between them and AQAP. An extended security operation offensive by STC forces against AQAP drove violence to sharply increase in 2022 to levels not seen since 2018, if far below the those witnessed prior to 2017, when AQAP was still capable of controlling major swathes of territory.
This resurgence of AQAP activity came amid a sharp decrease in US drone strikes following the inauguration of a new US administration at the start of 2021. US airstrikes first fell into the single digits in 2021, declining until there were with no recorded lethal US airstrikes against AQAP in 2024, marking the first year since the formation of AQAP in 2009 that there was no secondary warring support from the United States against AQAP. Violence decreased again in 2023, and dropped even further in 2024 as the security situation in the STC-governed regions solidified. The new Trump administration, inaugurated in 2025, reversed the decline in US airstrikes against AQAP, while violence increased during the year. In late-2025, STC broke with the PLC, leading to significant security disruption in southern Yemen. AQAP took advantage of the chaos to increase its attacks on the STC (at this time a separate non-state dyad: AQAP – STC).
The non-state conflict between AQAP and Forces of Hadi is first included in UCDP data in 2015. In February of that year, clashes between the two groups resulted in more than 25 battle-related deaths. The Ansarallah Government of Yemen has also occasionally fought AQAP, though the rate of fighting has steadily declined as AQAP weakened and lost ground, and was last active in 2018.
