(CNN) Sixteen years after the 9/11 attacks, there is a fair amount of good news about the state of the battle against jihadist terrorists: The United States has not suffered a successful attack by a foreign terrorist organization since al Qaeda's horrific attack on the World Trade Center and Pentagon.

Al Qaeda's core group, based in Afghanistan and Pakistan, hasn't launched a successful attack in the West since the suicide bombings on London's transportation system more than a decade ago in 2005, which killed 52 commuters.

The terrorist group that sprang up in the wake of the setbacks suffered by al Qaeda, ISIS is itself now largely defeated, having lost the city of Mosul, its headquarters in Iraq, and much of the city of Raqqa, its headquarters in Syria.

The US-led coalition has also killed an estimated 60,000 to 70,000 ISIS fighters, according to US Special Operations Command's Gen. Raymond "Tony" Thomas, speaking at the Aspen Security Forum in July.

A month later Brett McGurk, the US envoy to the anti-ISIS coalition, said ISIS had lost control of more than three-quarters of the territory that it had once held in Iraq and more than half of what it had once controlled in Syria.

The threat posed by American "foreign fighters" returning to the United States who were trained by ISIS or other jihadist groups in Iraq and Syria is quite low compared to European countries. According to public records, only seven American militants have returned from the Syrian and Iraqi battlefields and none has carried out an act of terrorism.

That's the good news, but there are other troubling trends. Since 2014 there have been six lethal jihadist terrorist attacks in the United States, killing 74 people, according to New America's research.

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Those attacks were carried out by American citizens and legal permanent residents, not by foreign terrorists as was the case on 9/11.

These American terrorists were inspired by ISIS propaganda online, but had no direct contact with the group.

Jihadist terrorists in the United States today overwhelmingly radicalize online. Of the 129 militants from the United States who joined jihadist terrorist groups in Iraq and Syria, or attempted to do so, or helped others to do so, 101 of them downloaded and shared jihadist propaganda online and some conducted encrypted online discussions with ISIS militants based in the Middle East, according to New America research.

The Israeli counterterrorism expert Gabriel Weimann rightly points out that the "lone wolf" is now part of a virtual pack.

In the cases of the 129 militants drawn to the Syrian conflict, none appears to have been recruited in person by other militant operatives.

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The Trump administration's temporary travel ban from six Muslim majority countries does nothing to address this "homegrown" militant threat that is enabled by jihadist propaganda online. Travel bans, of course, have no impact on the Internet.

While the United States has seen no lethal attacks in which the perpetrators were trained and directed by foreign terrorist organizations since 9/11, there have been five ISIS-directed attacks in Europe since 2014 that killed 188 people, around twice the death toll of all deadly jihadist attacks in the United States since 9/11.

Meanwhile, the Taliban in Afghanistan are at their strongest point since their defeat by US forces shortly after 9/11.

Other forms of political violence in the United States

Terrorism in the United States doesn't emanate only from jihadists, who have killed 95 people in the States since 9/11.

Individuals motivated by far-right ideology have killed 68 people in the United States during the same period, while individuals motivated by black nationalist ideology have killed eight people, according to New America research.

The drivers of terrorism

Even though ISIS is largely defeated, the conditions that led to the group's emergence largely remain, including the regional civil war in the Middle East between Sunni and Shia that has consumed Iraq, Syria and Yemen; the collapse of Arab governance around the region; the collapse of economies in war-torn Muslim states and the population bulge in the Middle East and North Africa.

This has precipitated a tidal wave of Muslim immigration into Europe. Those immigrants are arriving in countries where Muslims are often marginalized and this wave of Muslim immigration has helped fuel the recent rise of European ultranationalist parties. This is a combustible mix, which may help propel some European Muslims to subscribe to the tenets of militant jihadism.

These drivers of jihadism strongly suggest that a son of ISIS will form in coming years.

Even as ISIS suffers repeated setbacks, al Qaeda's branch in Syria has shown surprising resiliency and it's possible that a rump version of ISIS might merge with al Qaeda in Syria. The two groups split from each other in 2014.

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Al Qaeda's core group also seems to be grooming Hamza bin Laden, one of Osama bin Laden's sons, as a next generation leader. Hamza bin Laden, who is in his late twenties, has appeared in a number of al Qaeda media productions in recent years.

The continued resilience of al Qaeda in Syria and the fact that the drivers of global jihadism are not going away anytime soon suggests that the long war that began on 9/11 more than a decade and half ago has many years left before it finally sputters out.