Deciding how we should wage a successful war on terrorist groups such as al-Qaeda is a matter of strategy. And in strategy, thought always should precede action. Extravagant calls for more airline security - now, everywhere - miss the point.

A balanced strategy would promote safety, of course, but it also would encourage continued economic growth and safeguard civil liberties. It wouldn't trade off one priority for another. The call for more air marshals and added security at foreign airports is a case in point. There's nothing wrong with more security, but we need to weigh carefully the demands we place on other nations, particularly developing ones.

U.S. policy encourages these economies to deregulate their markets and embrace free trade. At the same time, we're imposing new security mandates that make it harder for them to compete in the global economy. Poorer countries, though, lack the expertise, technologies and infrastructure to add expensive security measures. Rather than just heap on more demands, we should give them technical assistance and reasonable options (lending them air marshals, for example) to help them provide more sophisticated levels of air safety.

Overall, adding additional layers of security makes sense. No one measure will be adequate to defeat every terrorist threat, and we need more tools that provide options, something other than either canceling flights or doing nothing. More important, though, than insisting that every program is airtight and unbeatable - or demanding that, say, Jackson Hole, Wyo., have the same security as New York's giant Kennedy airport - is ensuring that we have complimentary layers of security implemented by people who cooperate and share information with one another.

We can ensure better security by looking into measures that can be added along the whole security chain, rather than rushing to inspect every piece of air cargo (a policy that would all but ground our $27 billion air freight and express industry). Initiatives such as the Department of Homeland Security's "known shipper" program, which bars unidentified persons from putting cargo on passenger airlines, make more sense.

The Bush administration also is developing initiatives to keep dangerous people out. For example, today the Transportation Security Administration has a Computer Assisted Passenger Prescreening System (CAPPS) that uses such general criteria it wouldn't keep certain terrorists off an airplane. So now it's readying a follow-on system, CAPPS II, which will use government intelligence and law enforcement information to pick out passengers who might have malicious intent. The skies are steadily becoming less friendly for terrorists.

Sound strategy, not profligate spending and poorly thought-out programs, is the right answer.

James Jay Carafano is the Senior Fellow for Defense and Homeland Security at the Heritage Foundation and the author of Waltzing into The Cold War: The Struggle for Occupied Austria.