By David H. Schanzer, RTI International

Editor’s note: David Schanzer is co-director of the , a research collaborative initiative between RTI International, Duke University, the University of North Carolina at Chapel Hill, and the North Carolina Military Foundation.

DURHAM, N.C. — The terrifying, but unsuccessful, Christmas "underwear" bomber attack has given rise to calls for massive new expenditures in airport screening devices. Instead of reflexively making this multibillion dollar expenditure in response to the attack, we should take a hard look at the entire system we have in place for securing air travel to determine what combination of investments and policy changes will most effectively reduce the risks we face from terrorism.

We have been aware of the threat that explosive powders and gels pose to aviation security for many years. Full-body scanning devices that create an image of inert objects close to the body could increase the odds of catching a suicide bomber using these materials. But they will not eliminate this risk for a couple of reasons.

First, every technical system that relies on human judgment, as this one does, will have an error rate. Better technology will reduce the error rate, but mistakes will still be made.

More important, however, our adversaries will adapt to whatever technology that we put in place. They will probe its weaknesses and eventually find a way to circumvent it. In this instance, there is evidence that the underwear bomber may already have been adapting to the full-body scanners, as these machines intentionally blur the genital area for privacy concerns.

The terrorists can also shift the method of attack entirely. Recall that in 2002, a failed attack on an airliner with a shoulder-fired missile led to calls from Congress to place anti-missile technology on all commercial airlines. These calls were rejected due to the prohibitive cost of this countermeasure. But once we spend billions on full-body scans to shut off one avenue of attack, you can be sure that al-Qaeda will renew its interest in shoulder-launched missiles, or some other tactic.

All this could leave one to throw up your hands and say "why bother with anything?" But this is the wrong way to think about the problem as well. A defensive presence at the airports and other sensitive sites helps to deter simple, low-tech plots and makes the terrorists work as hard as possible (leaving clues along the way) to devise sophisticated ones. We need to take care, however, not to spend ourselves into oblivion trying to find the silver bullet technical solution or overspend on screening devices at the expense of investing in other defensive measures.

We get much more counterterrorism bang for the taxpayer buck by investing in intelligence, law enforcement and international coordination than expensive homeland security technologies. Stopping our enemies from getting a visa to enter the United States has to be our ultimate objective. After all, if Abdulmutallab had feared being caught by airport scanners, he still could have flown to the United States, assembled his bomb here, and blown himself up in a crowded subway. A multibillion dollar investment in full-body scanners is worthless against this threat.

Outrage about the Christmas attack should be focused much more on how our intelligence coordination failed than defects in passenger screening. For over eight years we have been assured that both interagency and international information sharing have dramatically improved since 9/11, yet a warning about Abdulmutallab from a highly credible source led to absolutely zero extra scrutiny as he waltzed through the international aviation system. And, we also failed to connect the dots between the tip on Abdulmutallab and the British government’s decision to deny him a visa. Clearly, there is dramatic room for improvement on this front.

Investments in intelligence analysts, consular officers, information sharing programs, and international meetings of key intelligence officials are not the types of flashy, visible security measures that government officials like to point to when demonstrating that they are doing "everything possible" to provide security to a jittery public. But these measures are probably more likely to reduce our overall risk to terrorism than the full-body scanners or the next fancy technology that governments across the world inevitably will be lining up to purchase, both today and for years to come.

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