The Wall Street Journal has an intriguing subhead on a news story about Orlando terrorist Omar Mateen:

Omar Mateen is an example of precisely the threat that has consumed the agency: terrorists in America whose self-radicalization is hard to spot.

I am wondering: what was so hard to spot about Omar Mateen's terrorist aspirations? Did he need to shout it from the rooftops? He all but did that:

The gunman authorities say massacred 49 people at an Orlando nightclub had proclaimed he wanted to be a martyr, traveled to Saudi Arabia and alarmed co-workers with claims of links to extremists—troubling hints of a homegrown terrorist but not enough to lead the Federal Bureau of Investigation to conclude he was a clear threat.

FBI Director James Comey, disclosing new details of Omar Mateen’s background Monday, said Mr. Mateen took trips to Saudi Arabia in 2011 and the following year, though Saudi and U.S. investigations found nothing suspicious.

According to the headline on the front page, Mateen "hinted" at  terror attack. Hinted? I'll say. The FBI investigated Mateen twice and and apparently gave him a clean bill of health twice. On this, Kyle Smith writes in today's New York Post:

Perhaps nothing could have been done to stop Mateen’s rampage, but I have a sickening suspicion that we’re going to learn that many more warnings went unseen by those who blindfolded themselves with political correctness.

Warnings were dismissed in the cases of the Boston Marathon bombers, Nidal Hassan, and the San Bernardino shooters. In the last a neighbor suspected the couple was up to no good, but kept quiet for fear of seeming to profile.

Somebody like Omar Mateen does pose complicated questions for a free society. We can't lock up people for expressing their views, however repellent.  But it does seem that there is a very high barrier for taking some common sense measures with regard to somebody who has issued some very loud "hints" that he means us harm.   

Still, as Charles Krauthammer noted, in a country this size, the FBI can mitigate the problem of individual terrorists, but it can't really solve it.

The solution, Krauthammer argued on the Fox panel, is by defeating these radicals at the source:

I think Brit Hume had it right – ultimately, the only way to decrease recruitment is not with logic, not with argument, not with really clever programmers who know how to do Twitter. It is by defeating the jihadists or showing them retreat.

These movements only grow when they have a sense of inevitability and growth. Once they’re in retreat, people stop recruiting. They’re not going to die in a suicide attack for a movement that is not advancing. And that means attacking ISIS where it is.

This has not been President Obama's way. Bret Stephens captures the Obama way with regard to terrorism:

King Canute of legend stood on an English shoreline and ordered the tide to recede. President Canute stood before a Beltway audience and ordered the war to end. Neither tide nor war obeyed.

Meanwhile, there are attempts to blame the slaughter on everything but radical Islam.