What would make otherwise normal people travel halfway around the globe to join a group of psychotic terrorists who behead for sport?

What is it about ISIS -- or the Islamic State group or whatever the heck it is we're calling them now -- that attracts recruits from Canada, the United States, Europe, Australia, Africa and Asia? Why would young women with full Western liberties and lives want to give up everything to succumb to Sharia law?

Those are questions the Obama administration and other foreign governments have to be pondering as they gin up not only an armed response to the threat of the Islamic State in Iraq and Syria, but also a propaganda war as well. Arsenals alone are not enough to stamp out Islamic extremism. The successful military fight waged against al-Qaida for the past 13 years proves that. We dispatched and imprisoned thousands of jihadists. Thousands more popped up. The radical Islamic ideology has to be destroyed, too, as do the reputations of its champions.

In a column a few weeks ago, I called on President Barack Obama to employ his crackerjack political team in that effort. The more we learn about the Islamic State and its leaders, the stronger I feel about that idea. (The Islamic State released a video this weekend on the third beheading of a Westerner in just weeks.)

U.S. intelligence should have thick dossiers on the habits and proclivities of the group's leaders, and their hypocrisies should blasted relentlessly around the world by wordsmiths who know how to make language hurt. I nominate Ed Rollins (Republican campaign consultant), David Axelrod (former senior adviser to President Obama), Karl Rove (former senior adviser to President George W. Bush) and Frank Luntz (Republican pollster) as the first candidates for national conscription.

But it still begs the question why a strict Islamic state, a caliphate, could be so attractive to young Muslims born and raised in the Western world. On Thursday we learned of a Twitter network streaming out of Syria calling itself the "Umm Network." (Umm is an Arabic nickname for mothers.) It claims to be comprised of 100 Western women who have traded in their passports for burqas and, potentially, stonings. Hundreds of other young jihadists regularly tweet Islamic State propaganda in perfect colloquial English to Muslims, and anyone else following, back in their home countries. Tweets can range from the mundane, such as, "What's everyone having for breakfast today?" to gruesome photos of executed civilians.

What the heck is that about? What is missing in these people's lives that would make them take such a drastic turn?

It is easy and convenient to label as lunatics expats who have joined the Islamic State and al-Qaida -- there is a case there -- but it can't be that simple. Here are people thirsting so badly for something that they're willing to go to extraordinary lengths to get it. What is it? I can't help thinking that the answer is purpose -- purpose and clear moral boundaries, things that are vanishing by the day in the West.

I'm not suggesting that Molly raves and meaningless sexual encounters lead to jihadism. There would be a lot more jihadists out there if that was the case. But the retreat of moral clarity and spirituality in modern Western culture can lead to an awful lot of emptiness and despair. I hear that every day in my personal and professional life. I hear people say they are missing . . . something. They can't quite put their fingers on it. It's just something.

Apparently that something can lead to very dark places for a certain few. If that thesis has merit, we're going to have to make a lot more Predator drones.