Islamic State leader Abu Ibrahim al-Hashimi al-Qurayshi died during a U.S. special forces raid on Thursday, dealing a setback to the terror group at the same time it’s been trying to stage a comeback.

“This is a major blow to ISIS and an important psychological victory for the U.S. team,”James Franklin Jeffrey, a former U.S. ambassador to Iraq, told NBC News.

President Biden told reporters that al-Qurayshi detonated a suicide bomb when cornered by U.S. special forces in his Syrian hideout. The bomb killed al-Qurayshi and several other people near him, including children. This was “a desperate act of cowardice,” Biden said, and similar to the way his predecessor Abu Bakr al-Baghdadi died in 2019.

Al-Qurayshi’s successor has not been identified, and it might stay that way, with ISIS keeping the name secret to protect him. “A lot of the leadership has been killed in the law few years,” Seth G. Jones, a counterterrorism expert at the Center for Strategic and International Studies,  told NBC News. “Because of that, they’re being very careful.”

Al-Qurayshi was from a region of Iraq where ethnic Turkmen make up the majority, and experts told NBC News they believe ISIS’ next leader will also be Iraqi. Dr. Daniel Milton, director of research at the Combatting Terrorism Center at West Point, told NBC News he thinks this person will be familiar with “Islamic jurisprudence” and have experience in the battlefield. ISIS has been planning for this moment, Jeffrey said, adding, “The shelf-life of an ISIS leader of late is about three years, and so they are prepared for that eventuality.”