There is an immediate and foolproof way to end terrorism against travelers: Ground all the planes.

Facetious as it sounds, the suggestion underlines an undeniable truth about traveling in a time of terror. The only air-travel system that is guaranteed to be secure is the one in which planes never fly. Anytime an airline puts a plane full of passengers in the sky, a complex web of political, financial, social, and governmental compromises have been made.

Keep that reality in mind as self-serving talking heads chatter in the aftermath of the Underwear Bomber's attempt to take down Northwest Flight 253 on Christmas Day. You can always make passengers and planes more secure than they already are. It just depends on how close you want to bring the system to a total halt. If you fly, you will have to accept some risk. If an airline operates, it will be in some danger. And if a nation permits commercial air travel, it creates a target for terrorists.

How do we improve our security without strangling air travel and the daily commerce that depends on it? There are some relatively simple and commonsense things we can do to reduce the risk that the next Underwear Bomber—or Shoe Bomber or Who-Knows-What-Article-of-Clothing Bomber—will kill travelers and create the kind of political and emotional havoc we've seen in the last two weeks.

Speak the Truth

Here's something that no politician, Republican or Democrat, will tell you: There will be a next time. Somehow, somewhere, someday, there will be another successful attack against a commercial airliner, and it won't necessarily mean our security regimens "failed." As a nation, we've been fighting the "war on terror" in the skies since the early 1960s, when the first lone gunman walked onto a plane, waved a revolver, and yelled, "Take this plane to Cuba!" There is no such thing as zero-incident airline security, and anyone who tells you otherwise is lying or seeking your vote. Or, probably, both. Knowing that we can't reach security perfection in the real world doesn't make us safer, of course, but it will help us curb our more reactionary and counterproductive instincts about the next attack.

Stop the Panic

It's never pleasant to play the numbers game when people's lives are on the line, but there is no other way to dispassionately portray the situation. According to Nate Silver, the math man who runs FiveThirtyEight.com, the odds of a flight being involved in a terrorist incident is currently one in 16.5 million. The odds of being struck by lightning? One in 500,000. So while we shouldn't make light of the Underwear Bomber, we shouldn't be conducting a debate about airline security as if the sky is falling. The firmament is intact, and the system is actually pretty secure. We are not in imminent danger every time we board an aircraft, and we shouldn't act as if we are. Blind panic is exactly what terrorists want.

Use Intelligence Intelligently

The last two terrorist incidents—the 2002 Shoe Bomber on an American Airlines flight from Paris and last month's Underwear Bomber—were literally predictable. U.S. intelligence services knew about both men. In fact, American Airlines barred Shoe Bomber Richard Reid from a flight just a day earlier, and the Underwear Bomber was on a government watch list.

In the years since 9/11, U.S. security services and the Transportation Security Administration have been awash in data about potential threats to the commercial-air system. Yet they have not always shared and correlated the intelligence intelligently. Deputy National Security Director John Brennan even had an alibi for missing the warning signs about the Underwear Bomber. "There is no smoking gun," he said on one of the Sunday talk shows. "There was no single piece of intelligence that said, 'This guy is going to get on a plane.'" Besides the obvious joke—maybe Brennan and his underlings should have been looking for smoking underwear—isn't it the job of Brennan's intelligence services to connect the dots before there is a smoking gun?