Osama bin Laden had made targeting the United States a top priority of his al-Qaida terrorist organization. Al-Qaida translates from Arabic as “the base” – a base that bin Laden hoped to use to influence Muslims around the world to oppose Western influences and states and to establish fundamentalist Islamic regimes. Bin Laden’s motives were rooted in his extremist interpretation of Islamic theology, resentment over U.S. foreign policy in the Middle East, and a desire to overthrow the existing world order.

The “base” was so-called due to it being a centralized, hierarchical organization that provided funding, training and logistical support to terrorism worldwide, including for the so-called “Planes Operation” of Sept. 11, 2001.

In order to embolden and support his organization, bin Laden often videotaped himself with messages aimed at his target audience, established training centers in Afghanistan, had an expansive funding network that included wealthy individuals, couriers, mosques and other complex ways to raise funds.

Bin Laden, through the al-Qaida terrorist organization, targeted the United States for nearly a decade before the 9/11 attacks in 2001, utilizing this large and expansive infrastructure. While al-Qaida’s 1998 attacks against U.S. embassies in Africa and the 2000 attack against the U.S. Navy guided missile destroyer USS Cole were successful, the organization’s largest operation was the Sept. 11, 2001, attacks against the World Trade Center in New York City, the Pentagon, and the thwarted attack on Washington, D.C., that ended with the crash of United Airlines Flight 93 in Shanksville, Pa. – all of which included recruiting and training the nineteen terrorist operatives, funding their travel and expenses, and time.

It took bin Laden almost two years to put together the resources and training necessary for those attacks 24 years ago – something that today could be done almost instantly.

Bin Laden and the 9/11 attacks lacked something that present-day terrorists, criminals and violent extremists have ready access to: the internet and, specifically, the dark web. After the 9/11 attacks, as the United States was ramping up to attack al-Qaida, “the base” and affiliate organizations began moving to a more decentralized and incentivized form of terrorism and violence.

Terrorists expanded their use of the internet for a wide range of activities, including planning attacks, radicalization and recruitment, propaganda dissemination, and fundraising. While the internet facilitates covert planning through tools like encrypted messages, it also serves as a platform for psychological warfare, spreading disinformation and images to incite fear. This online presence includes social media platforms used for propaganda, communication and recruitment, creating a challenge for governments and platforms alike to manage the spread of extremist content in hopes of preventing potential violence.

In a 2004 study, the United States Institute of Peace said that hundreds of terrorist groups had migrated online, utilizing a tool meant for better communication for often nefarious purposes. Nearly 20 years later, a 2022 study titled Terrorism and the internet: How dangerous is online radicalization? highlighted how online radicalization had become a clear threat that can metastasize in dark corners, often unnoticed.

The main use of the internet by these terrorist groups – incentivizing and radicalizing supporters and stoking fear with propaganda – is something bin Laden would have had to do with videotapes played by the news. Likewise, the internet has made fundraising much easier with the use of online payment methods, which are easy to set up and difficult to trace. And now, with the advent of generative artificial intelligence (AI), terrorists have yet another tool at their disposal.

According to a U.S. House of Representatives Committee on Homeland Security hearing background advisory earlier this year, “GenAI is a rapidly emerging technology that can produce numerous kinds of content, such as text, images, or audio, when prompted by a user. Foreign terrorist organizations are actively seeking ways to exploit GenAI to support a variety of violent extremist tactics, techniques, and procedures, such as using AI-powered chatbots, to interact with potential recruits.”

“Foreign cloud-based mobile and desktop messaging applications like TikTok and Telegram have allowed their platforms to become a breeding ground for radical extremism,” the advisory continued. Essentially, terrorist groups have been able to weaponize the internet and incite violence in ways they couldn’t have imagined on Sept. 11.

While terrorism isn’t new, the use of the internet, and now AI, magnifies the capabilities and reach of terrorist groups that used to rely on scattered notes and videotapes to conduct their business. It seems reasonable to assume that if bin Laden had had access to the technologies of today, the 9/11 attacks may have been precursors to additional and more frequent deadly attacks.

The threats we face today are more complex, borderless, and technologically advanced than ever before. Counterterrorism strategies must continue to adapt to meet this evolving battleground, leveraging not only military and intelligence tools but also public-private partnerships with tech platforms, AI monitoring, and global diplomacy.

The legacy of 9/11 must be more than remembrance – it must be vigilance. As we honor the nearly 3,000 lives lost that day, and those first responders who have died in the years since, we must remain resolute in facing the ever-changing face of extremism, now armed with digital weapons and invisible armies.

Richard F. Frankel is an ABC News contributor and former special agent in charge for the FBI. Donald J. Mihalek is an ABC News contributor, retired senior Secret Service agent and regional field training instructor who served on the president’s detail and presidential transitions. The opinions expressed in this story are theirs and not those of ABC News.