Terrorist cowards struck mass transit sites in London causing death and destruction. And after “the usual sources” had dispensed with their rounds of blaming the United States, as so many do in matters of tragedy anywhere on the globe, there were expected calls for vast enhancement of public transport security.

The New York governor’s office said the attacks should be a “wake-up” call to Washington and President Bush. U.S. Sens. Charles Schumer and Hillary Clinton, with New York subway ties, called for much more money to be added to homeland security spending. Schumer said at least $200 million must be spent while Clinton used a figure of $1.3 billion. Transportation lobbyists contend they need at least $6 billion to “upgrade” security.

Money, however, will never be as effective as alert people.

Every reasonable means must be employed to deal with terror threats on mass transit, but there is absolutely no fail-safe solution. Further, what about all the other public arenas that also need more protection? At what cost? Terrorists have the luxury of being able to operate “on the cheap” with crude bombs and death-seeking suicide freaks and need be “correct” only once. For protectors, nothing less than 100 percent success is acceptable.

After the early emotions about the London carnage and how it can be dealt with, some reasonable analyses have emerged. They are far more practical than costly. Anne Applebaum of the Washington Post put it best when she wrote:

“Here’s the truth about mass transit security. There is no technology that can guarantee it. There are no machines that can reliably detect the presence of a backpack filled with homemade explosives in an underground tunnel. There is no point in putting metal detectors at every single subway entrance or at every single bus stop. There is no amount of money, in other words, that can guarantee that subways and buses will be completely safe from small-time bombers, suicide or otherwise. It’s going to be a temptation, especially for Washingtonians, New Yorkers and others who regularly ride mass transit, to lobby their politicians for more spending. Don’t do it.

“If that makes you feel queasy, or powerless, or claustrophobic, then do the one thing passengers actually can do: Keep your eyes open for unattended packages, and if you see one, say so out loud. The Madrid bombs may have been left by terrorists who exited the trains. Maybe a sharp-eyed passenger could have called attention to the packages before they exploded. : A little forethought goes a longer way, in the current climate, than a load of technology.”

We’re all in this together, and an alert citizenry has the potential to combat terrorism far better than billions of dollars for questionable security measures that can so easily be thwarted by well-informed sources out to do us in.