Hamza bin Laden, the son and heir of Osama bin Laden, is almost certainly dead.

While his demise has not yet been confirmed by al-Qaeda, U.S. officials have felt confident enough to brief media outlets that the younger bin Laden was killed at some point after January 2017.

It’s unclear to what extent the U.S. was involved and exactly where the killing of Hamza bin Laden took place. However, for years, much of al-Qaeda’s central leadership has been lying low in northwest Pakistan.

There has been speculation for some time that, as the son of al-Qaeda’s former leader, he was being groomed for a leadership role within the terror group in the years ahead.

His profile was growing as Hamza, said to be born in 1989, appeared more frequently in al-Qaeda’s propaganda output, calling for attacks in the U.S., United Kingdom, and elsewhere.

Though not a veteran warrior, Hamza bin Laden enjoyed star power within jihadist circles due to his father’s legacy. He potentially represented al-Qaeda’s future, so his death is clearly a blow to the terror network.

However, al-Qaeda has had to get used to losing key personnel over the past 18 years. The U.S. has killed and captured countless top al-Qaeda leaders—be they in Pakistan, Afghanistan, Yemen, Somalia, Syria, or elsewhere—and yet the group has still managed to rebound.

So while this is a heavy blow to al-Qaeda, it is unlikely to be a fatal one.

That matters, because al-Qaeda is a group that still aspires to attack America. As recently as November 2016, al-Qaeda was thought to be planning a possible attack before the election. The U.S. responded by launching drone strikes against the group in Afghanistan, Syria, and Yemen.

The Trump administration must remain committed to keeping pressure on al-Qaeda as part of a broader counterterrorism strategy.

Undoubtedly, the administration has achieved success on this front. Destroying the ISIS caliphate in Iraq and Syria was a particularly key moment. So, too, was the drone strike that killed the notorious bomb-maker Ibrahim al-Asiri, affiliated with al-Qaeda in the Arabian Peninsula.

Still, the threat from ISIS rumbles on, and an array of jihadist groups continues to operate throughout the Middle East, Africa, and Asia. In addition, there are homegrown Islamist terrorists based within the U.S. who aspire to strike the homeland.

One such attack occurred in October 2017, when an Uzbek man killed eight and injured a dozen others by mowing them down with a truck in New York City.

Two months later, a Bangladeshi man attempted to carry out a suicide bombing, also in New York City. While the bomb detonated, it thankfully didn’t claim any casualties. Many other plots targeting the U.S. have since been thwarted by law enforcement.

The U.S. needs to remain vigilant. It needs to keep identifying key terrorist leaders overseas, and then either kill or capture them. It also needs to keep a watchful eye on potential threats based within the U.S..

Thankfully, the U.S. has top-notch intelligence and law enforcement agencies who are up to the task.

But physical security is not enough. The U.S. also needs to work with key partners and allies at a state and non-state level to reduce the ideological appeal of Islamism.

The Islamist threat will come to an end only when the ideas that animate the movement are entirely discredited. Unfortunately, that’s the area where much work still remains to be done both in the U.S. and beyond.

Still, that is a task for tomorrow. Today, the U.S. can be thankful that Osama bin Laden’s hateful legacy will likely no longer be being promulgated by his son.