It was only natural in the wake of 9/11 that Americans would be galvanized by the destruction of the Twin Towers. The disaster that played out live on television could hardly be ignored. In the years that followed, the country was terrified of terrorism and largely united in the quest to stamp it out.

As tends to happen, of course, the fear died away. It was replaced by apathy, by anger at the American government, and by concerns over the domestic economy. Even sporadic reminders that there is an enemy that wants to kill Americans at home and abroad have not been enough to rejuvenate that early panic. While that’s a good thing (the Bush administration went a bit too far in seizing federal power in the name of protecting the homeland), has it perhaps swung too far in the opposite direction? Are Americans losing sight of the potent enemy that is extremist Islam, even as its most fervent believers cut a swath towards Baghdad?

Over at The National Interest magazine, Daniel R. DePetris put together a list of the five most dangerous terrorist organizations on the planet. It should come as no surprise to anyone that they are all five based on radical Islam. Despite what the left claims, these terror groups have as much claim to the religion as its billions of peaceful followers. And while those peaceful followers should not be condemned by association, there comes a time when you have to face the facts about your enemy. To pretend as though Islamic terrorism is somehow separate from the Islam in general is irresponsible and dangerous.

The Five Deadliest Groups

ISIS in Iraq and Syria, Boko Haram in Nigeria, Islamic Revolutionary Guard Corps-Quds Force in Iran, the Haqqani Network in Afghanistan, and Kataib Hezbollah in Iraq are the five deadliest terror organizations in the world, according to DePetris. They all share two things in common: a base in the Middle East and a belief in radical versions of Islam. Their specific aims differ, but they are one in the same when it comes to their conviction that the world should be run according to Islamic law. Standing in their way are a number of obstacles, but Israel and the United States are certainly at or near the top of that list.

Experts think we may never see another attack on American soil that rivals that devastating day in late 2001. Our security is too strong, they say. Our counterterrorism efforts are too coordinated. What we will see instead are so-called “lone wolf” attacks. We will see Americans radicalized by the Internet, driven to extreme measures like the shooter in Ottawa, the beheader in Oklahoma, and the hatchet-wielding attacker in New York City.

But even one man radicalized by online propaganda can do a world of harm. One need look no further than the devastation caused by Timothy McVeigh to see how much evil a man is capable of if he has the will.

When the Democrats were fishing about for excuses that would explain their midterm losses, they called ISIS a “distraction” that confused voters on the way to election day. But ISIS is no distraction. Nor are they the only ones. America must not live in fear of terrorism, but we also must remain vigilant against it.