ISIS: Continues to Withstand Leadership Losses

A History of Resilience

Since the declaration of its self-proclaimed “caliphate” in 2014, ISIS and its predecessor group—al-Qa’ida in Iraq (AQI)—have adapted to substantial setbacks. 

  • In 2006, AQI’s founder, Abu Musab al-Zarqawi, was killed in a coalition airstrike, but the group replaced him within five days with Abu Ayyub al-Masri.
  • Between 2006-11, US-led coalition forces killed or detained 36 of its 42 leaders, and 11,000 fighters were assassinated or captured, according to US officials. Yet in 2012-13, AQI launched a year-long “Breaking the Walls” campaign, releasing AQI members from jail to replenish its ranks.
  • In 2013, AQI reemerged as ISIS and conducted approximately 40 suicide bombings per month in Iraq—achieving the highest civilian death toll since 2008. When ISIS leader Abu Bakr al-Baghdadi announced the establishment of the caliphate in 2014, the group was the richest militant organization in the world, controlled significant swaths of land in Iraq and Syria, and had approximately 20,000 to 30,000 fighters, according to US estimates.

Recovery After Propagandist Fatalities

Despite key propagandist losses, ISIS continues to disseminate information encouraging supporters to conduct attacks and recruit members. Between August 2016 and January 2017, three ISIS propagandists were killed in US-led coalition airstrikes.

Potential Impact of Baghdadi’s Death

NJOHSP assesses Abu Bakr al-Baghdadi’s death would not impact the group’s long-term capabilities, owing to its decentralized leadership structure and ability to encourage followers to conduct external attacks in the West. Since the establishment of the caliphate, hundreds of ISIS leaders have been killed in coalition airstrikes—120 in 2016 alone. 

  • In 2015, Baghdadi delegated more power and autonomy to regional and military commanders in Iraq and Syria to ensure minimal disruption to the group’s operations in the event of his death or those of top leaders, according to US and Iraqi intelligence officials.
  • In April, following reports of Baghdadi being injured, the Shura Council allegedly selected a future replacement, Abu Hafsah al-Mosuli—a senior ISIS leader serving as the governor of Iraq’s Ninawa Province. In the event of Baghdadi’s death, the Shura Council will likely appoint Mosuli as the group’s next leader.
  • ISIS continues to encourage followers to execute attacks in the West, including the United States. Since October 2016, the group has adopted a refined, detail-oriented strategy to inspire homegrown violent extremists, resulting in seven attacks in the West—including those in Germany, France, England, and the United States.

For more information, please contact NJOHSP's Analysis Bureau at or 609-584-4000.