The following editorial appeared in the Chicago Tribune.

Were Akayed Ullah a more accomplished suicide bomber, we might have been writing about the horrible repercussions of mass casualties in New York City’s subway just days before Christmas. Fortunately, Ullah’s makeshift bomb failed to fully detonate; he was most seriously injured in his own attack.

“I did it for Islamic State,” Ullah reportedly told investigators.

You may ask: What remains of Islamic State?

In recent weeks the U.S. and its partners have crushed the last remnants of Islamic State fighters in Iraq and Syria. The terrorists’ dream of an empire lies in shambles. We had hoped that the defeat of Islamic State on the battlefield would demolish the group’s recruiting appeal. Unfortunately not. Its violent message still inspires willing wannabes via cyberspace. One British counterterrorism official warns that there is “incitement to attack through the internet, 24/7.”

There’s much more work to be done before the U.S. can declare VI Day.

There is progress. The U.S. has choked off potential terror recruits’ efforts to gain weapons training overseas. Instead, Islamic State devotees have turned to tutorials on encrypted communications channels, The New York Times reports.

The recent subway tunnel bombing was the third terrorist attack in New York City in about 15 months. Truck attacks, suicide bombings — more common in European capitals and the Middle East — are now moving up the list of potential threats to U.S. cities. There are two reasons: These attacks take little expertise, planning or money; and they’re nearly impossible for law enforcement to detect and thwart.

Eradicating Islamic State on the military battlefield may prove easier than expunging its call to arms on the internet. Cyberspace’s borders are infinite; authorities may play whack-a-mole against websites that hoist the banner of hate.

But let’s remember that just two years ago, the ground war against Islamic State raged. Fighters from 90 countries poured into Iraq and Syria. Former CIA Deputy Director Michael Morell wrote in Time magazine in 2015: “The nature and significance of the threat flow from the fact that (Islamic State) is — all at the same time — a terrorist group, a state and a revolutionary political movement. We have never faced an adversary like it.”

Islamic State is no longer a state. But the threat evolves. Terrorists routed from one place regroup elsewhere. Islamic State may be poised to grow in Central Asia. Authorities also warn that thousands of former fighters may be returning from battle to set up shop in parts of Africa.

In a related security issue, President Donald Trump, like his predecessor, seeks to bolster America’s prowess on the electronic battlefield — not just against Islamic State but all terror groups. This includes eavesdropping on terrorist phone calls overseas, sweeping up emails and texts. The law that allows such surveillance, Section 702 of the Foreign Intelligence Surveillance Amendments Act, expires at year’s end. We urge Congress to renew it without delay.