Once spanning a large swath of Iraq and Syria, the self-declared caliphate Islamic State was delivered a seeming deathblow in October: United States special forces killed the group’s leader, Abu Bakr al-Baghdadi.

But the militant group, which arose from the remnants of al-Qaida in Iraq after that group’s defeat by U.S.-led forces in 2008, spent little time mourning before pushing forward.

“Less than a week after Abu Bakr al Baghdadi detonated himself rather than risk capture, the Islamic State named his successor,” Washington Examiner reported. “‘We give our obedience to the commander of the faithful, the caliph of the Muslims, Abu Ibrahim al Hashimi al Qurayshi, pledging to listen and obey, in times of delight and dislike, and in times of hardship and ease, and to do so selflessly,’ the group’s new spokesman announced.”

The Examiner article concluded, “ISIS’s continued resonance among a subset of extremist Islamists worldwide, meanwhile, will make Baghdadi’s death simply the conclusion of a chapter rather than the end of the story.”

The Islamic State remains a dangerous threat in Iraq, Afghanistan and beyond.

U.S. forces, perhaps in reduced numbers, will continue hunting and attacking key Islamic State targets, even as President Donald Trump says he is committed to a 2016 campaign pledge to bring them home to cease the “endless wars” started under his predecessors.

Mr. Trump suggested that other countries, including Russia, carry on the fight against ISIS, but there is no indication that U.S. forces will abandon the mission any time soon.

The general sentiment: America cannot get smug now, or just leave it to others. Do not underestimate ISIS’ ability to make a fast comeback.

“Our job is to stay on top of that and to make sure that we continue to take out their leadership,” Defense Secretary Mark Esper said on ABC’s “This Week.”

According to defense officials in Iraq and Afghanistan tasked with watching the Islamic State’s movements, the group is growing in power and numbers outside of Syria.

Western leaders know this and are focusing efforts on stopping ISIS from strengthening under new leadership.

Pervasive Mindset

Social media posts by groups affiliated with ISIS note that the death of a leader does not spell the end of an ideology.

“Jihad has not stopped with the death of a leader or Emir,” said a post on Shmoukh al-Islam page, translated as “glory of Islam.” It added: “What if the leader of the Believers is martyred, we will stay the course and to whoever follows we renew the pledge.”

Al-Baghdadi’s jihad tactics are alive and well.

A key to ISIS’s macabre success is its “kill where you are” ethos. It encourages a far-flung network of followers, including those in the United States, to commit violence however and wherever they can.

That message, which bred the infamous attacks in Nice, France, and at Manchester Arena in England, lives on.

Militants under al-Baghdadi’s command were some of the first jihadis to grow up with the internet, and they deftly exploit social media to tout their military successes, document their mass slaughter, beheadings and stonings, and promote the Islamic State to a global audience.

When President Barack Obama launched airstrikes against ISIS beginning in August 2014, Islamic State militants responded by beheading Western captives and posting the video footage online. American journalist James Foley was among the first.

A few months later, an online audio message purportedly from al-Baghdadi urged his followers to “explode the volcanoes of jihad everywhere.”

Since then the group has carried out countless kidnappings, car and suicide bombings in public places, and shootings of civilians and police. ISIS is infamous for using civilians as human shields.

According to the U.S. Department of State Country Reports on Terrorism 2018: “Since at least 2015, the group has integrated local children and children of foreign terrorist fighters into its forces and used them as executioners and suicide attackers. ISIS has systematically prepared child soldiers in Iraq and Syria using its education and religious infrastructure as part of its training and recruitment of members. Further, since 2015, ISIS abducted, raped, and abused thousands of women and children, some as young as eight years old. Women and children were sold and enslaved, distributed to ISIS fighters as spoils of war, forced into marriage and domestic servitude, or subjected to physical and sexual abuse.”

While still alive, al-Baghdadi served as a direct inspiration for extremists abroad. In the U.S., multiple jihadists in the last five years invoked his name as they carried out murderous acts.

Omar Mateen, the gunman who in 2016 killed 49 people inside a Florida nightclub, pledged allegiance to al-Baghdadi during a 911 call in which he identified himself as an Islamic soldier.

Months earlier, Tashfeen Malik along with her husband killed 14 people at a party in Southern California. During the massacre, she posted her support for al-Baghdadi on Facebook.

“That voice, the face associated with it—the name in particular—it’s all directly linked to those in the United States who have pledged allegiance to him so as to conduct attacks in the group’s name,” said Joshua Geltzer, a former senior counterterrorism official in the Obama administration.

Beyond an Ideology

On April 30, 2019, al-Baghdadi appeared in a video acknowledging defeat in the group’s last stronghold in Syria but vowing a “long battle” ahead. He had a bushy gray and red beard, wearing a black robe with a beige vest and seated on the floor with what appeared to be an AK-74 rifle propped up next to him.

The terror leader also claimed responsibility for the Easter bombings in Sri Lanka that killed over 250 people as “part of the revenge” on the West.

“Our battle today is a war of attrition to harm the enemy, and they should know that jihad will continue until doomsday,” he said.

Having struck down one leader will likely only scatter loyal followers temporarily. What this extremist group pursues can outlive any leader, and it begins to underscore the sobering reality behind the persistent threat of ISIS.

In the 2016 Real Truth article, “Why Stopping Terrorism Is Harder than You Think,” terrorism expert Dr. James Pastor commented on the group’s future: “Ironically, if their caliphate is destroyed, which seems imminent, ISIS likely poses an even bigger threat. They will have a choice to make: Do they fold up their tent, abandon the idea of a caliphate, and cease to exist? Or do they export action directly into the West? The short-term answer is predictable: they will redirect their approach from securing land to exporting terror. After all, it was the West, with the help of the Iraqis and Kurds, that have caused the caliphate’s demise.”

Further, Dr. Pastor stated: “The people who run ISIS are, frankly, just like kingpins in the Mafia or leaders of a gang. They run an organization that pushes an ideological framework. The organization is just a name that is run by people. But ultimately the name and the people are not that important. What’s really important for them is the movement. If ISIS is defeated, there will be another name that will take the baton or move the ball in terms of fostering the goal of a worldwide caliphate.”

Now that ISIS has been driven out of its territory in Syria and Iraq, other experts have confirmed its ideology continues to exist and spread. “I’ve always said, yes, I will celebrate when Baghdadi is dead, but at the same time, that celebration is quiet and quick, because there are other Baghdadis out there who have been radicalized,” said Chris Costa, a former senior director for counterterrorism on the National Security Council.

That statement should bring pause. What does he mean, “there are other Baghdadis out there”? And the bigger question is, why are there still “other Baghdadis out there”?

Answering this requires understanding what it takes to stop an enemy.

Defeating Two Caliphates

According to the U.S. Army Counterinsurgency Warrior Handbook, defeat is defined as “when an enemy force has temporarily or permanently lost the physical means or the will to fight.”

Indeed, armed forces have taken away the terrorist organization’s physical means to fight by killing, wounding or capturing those in the physical caliphate, including al-Baghdadi.

But defeating the virtual caliphate—individuals and groups around the globe radicalized by the Islamic State’s ideals through the internet—is next to impossible. In this case, stemming the “will to fight” involves a virtual struggle.

“Over time, internet has become an indispensable tool for the Islamic State—a tool they have used with much efficacy for all their operations ranging from spreading propaganda, recruitment, communication, planning, financing and execution,” Observer Research Foundation reported.

“They have been able to survive and expand their presence across the world with the help of the internet, despite surveillance measures taken by governments and technology companies because of the wide array of options at their disposal.”

The stabbing attacks in the Hague and London in November prove ISIS’s ability to wage jihad beyond al-Baghdadi. The internet is why these attacks occurred.

“Terrorist groups use mass social media platforms such as Twitter, Facebook and Instagram to accomplish as much interaction as possible in as little time as possible, given the efforts made by governments and technology companies to remove terroristic content from their platforms at the earliest opportunity,” ORF continued. “However, these measures have not been very successful because of the sheer volume of bot accounts that are created. New accounts are ready to be used as soon as old ones are taken off.”

Those who contact the groups do so through encrypted apps such as Telegram, Kik or WhatsApp. Many who do are then radicalized and encouraged to wage violence.

This is what makes defeating the terrorist group’s will to fight practically impossible. According to the Council on Foreign Relations: “With the Islamic State going ‘underground’ by moving to encrypted, less open digital communications, counter-intelligence becomes more important but increasingly difficult and controversial. The shift to using the internet to facilitate conventional terrorist attacks keeps the need for counter-content efforts urgent, but finding and removing extremist content online will become more difficult as Western social media becomes less important.”

As counterterrorist agencies struggle against virtual-fueled terrorism, the world will continue to contend with its effects.

Ultimately, unless the internet itself is eliminated or fundamentally changed, ISIS’s survival is all but ensured.