The aftermath of Hurricane Katrina has already been alleged by various commentators to have "demonstrated" an improbably large number of propositions. These include the incompetence of the mayor and municipal government of New Orleans, the governor and state of Louisiana, and/or the president and federal government of the United States; the poor organizational structure of FEMA; the relative efficiency of the military over the civilian bureaucracy; the short-sightedness of congressional appropriators; the pervasiveness of poverty in America; the dangers of global warming and insufficient wetlands protection; liberal media bias; the propensity of the welfare state to foster a dysfunctional culture; the error of deploying National Guard troops in Iraq; and either the compassion or the racism of white Americans. Needless to say, not all can be correct, and even those that are not logically exclusive are unlikely to be true in equal measures.

It might seem gratuitous to add another demonstration to the list, but there is at least one that has been little remarked upon thus far.

Hurricane Katrina has demonstrated that George W. Bush’s forward-based offensive strategy against terrorism is essential.

How, one might ask, did it do that?

It demonstrated the folly of the nation placing its primary trust in Homeland Security preparations to mitigate and respond to a terrorist attack on a major U.S. city.

There are essentially three potential methods of approaching the threat of terrorism. First, one can use law enforcement to try to intercept individual terrorists after they enter the U.S. or allied countries but before they strike. This element is important but is fundamentally defensive in character and relies on superb intelligence and a great deal of luck. It also depends on laws, similar to the PATRIOT Act, permitting vigorous intelligence and interception techniques which most liberals, some conservatives, and the ACLU cannot abide.

Second, one can make preparations at potential points of attack in hopes of foiling an attack at the last minute and, failing that, responding to the carnage in a way that saves the most possible lives. In its fullest extent, this strategy is prohibitively costly, as one attempts to guard all possible targets and prepare for all possible catastrophes. Even if one concentrates only on likely or high-priority targets, it is fundamentally both defensive and passive, content to absorb blows and pick up the pieces. Katrina has made two points. Violent events—and Katrina has been compared by some to the devastation inflicted by a nuclear weapon—are capable of inflicting damage on American cities well beyond what most Americans had been able to comprehend, and well beyond what they consider tolerable. And that damage can be great enough to unhinge any plans government at all levels might have to deal with it. The Department of Homeland Security’s 400-plus page long "master plan" for disasters did not survive its first disaster. While, as the saying goes, "mistakes were made," the reason for this failure goes much deeper than flaws in execution. The central problem is that the response to a disaster of this scale—any disaster of this scale—will always fall short, given human imperfection and bureaucratic rigidities. A nuclear, biological, or chemical attack by terrorists will see similar devastation and similar chaos, no matter how well-ordered the plan and no matter how competent the men charged with executing it. The upshot is that passive defense may be an unavoidable strategy when dealing with a hurricane, but it is an unacceptable one when dealing with terrorists, except in a supporting role. It is and must be "Plan C," what is done after everything else has failed.

This leaves the third stratagem, a forward-based offensive strategy. And indeed, if it were possible to launch a preemptive strike to disable Katrina before landfall, is there an American who would not have urged it? Such a strategy would identify the groups that threaten America and the governments that harbor them or might pass on them the sort of weapons that could produce a man-made Katrina, then would undertake to destroy them root and branch. It would also seek to change the political culture of fanaticism and tyranny which serves as the incubator of the threat. It would not wait for the blow to fall and then hope that the governor knows when to call out the National Guard to protect the rubble.

This, of course, looks a great deal like George Bush’s anti-terrorism policy, and why, despite erosion, his anti-terrorism effort is still rated by the public as his strongest point. He, and Americans, have been driven to it not by choice but by logic and necessity.

Of course, a complete anti-terrorism strategy relies on all three components—interception, local response, and forward offense. Liberals, however, seem determined the knock the legs out from under both interception and offense, leaving us with little but a passive hope that, for the sake of the survivors of the next terror attack, the new FEMA head will be better than the last one. Call it the Katrina Option.

Andrew E. Busch is a Professor of Government at Claremont McKenna College and an Adjunct Fellow of the Ashbrook Center.