The horrific September 11 attacks will change forever the way we assess threats to the United States. This catastrophe crossed the line from conventional terrorism to terrorism with weapons of mass destruction. The terrorists caused thousands of casualties not with chemical, biological or nuclear agents, but with aviation fuel. As the victims are recovered and remembered, the attacks should force a painful reappraisal of the threats all nations face in the 21st century.

No one had anticipated or predicted attacks on the scale and with the coordination of the explosions in New York and Washington. But experts have warned of similar possibilities for years, particularly after the 1993 attack on the World Trade Center came so close to collapsing the buildings with conventional truck bombs. This February, Director of the Defense Intelligence Agency Admiral Thomas Wilson told Congress that over the next 12 to 24 months, he feared "a major terrorist attack against United States interests, either here or abroad, perhaps with a weapon designed to produce mass casualties."

What most experts meant by mass casualties, however, focused on terrorist use of chemical or biological agents, or radiological weapons (conventional explosives laced with radioactive materials). Terrorism expert Frank Cilluffo, for example, warned in Senate testimony on September 5 that "There is a real danger of being overwhelmed - two simultaneous bombings of the magnitude of Oklahoma City or a large-scale release of sarin or VX nerve gas - could strain our current system to the point of bursting." The ultimate fear was terrorist use of a "suitcase bomb" stolen from or built with nuclear material from Russia.

Separately, military researchers in the United States and elsewhere have constructed "fuel-air" bombs that, by spraying and igniting a ball of fuel, can produce explosions with the power of a small nuclear device. The September terrorists created this same effect by using airplanes loaded with fuel for cross-country flight that exploded with an estimated force of one thousand tons of TNT, or one kiloton, in a dense population center. The World Trade Center explosions themselves undoubtedly killed hundreds, but the collapse of the towers sent the casualties soaring past any previous historical experience.

This should be a transforming event in the way America evaluates its national security threats. We worried about expensive, sophisticated weapons developed by powerful nations during the Cold War and now pursued by a few "rogue states." But the terror came low-tech. The terrorist studied flight manuals not chemistry, biology or physics. They didn't build missiles; they stole what they needed and turned our own technological marvels against us.

The day before the attacks, Chairman of the Senate Foreign Relations Committee Joseph Biden almost prophetically warned of an exclusive focus on missile defenses. He cited the Joint Chiefs to support his view that a strategic nuclear attack "is less likely than regional conflicts, or major theater wars or terrorist attacks at home and abroad." If we spend billions on missile defense, he feared, "We will have diverted all that money to address the least likely threat while the real threats come into this country in the hold of ship, or the belly of a plane or are smuggled into a city in the middle of the night in a vial in a backpack."

Sadly, he can now add, "in a kamikaze attack."

As the nation mourns, this should be a moment when experts and political leaders forge a common cause - to compromise individual agendas for the sake of a unified response to those who attack this country. Surely there is a way to pursue missile defense research, while shifting some funds to airport security and counter-intelligence operations. We can stay concerned about rogue nations, but focus now on the few, small groups of transnational terrorists. We can update treaties where necessary, but still reinforce international alliances to isolate those who operate beyond the pale. We can pursue and punish those responsible, while re-engaging in efforts to resolve the underlying conflicts that breed terrorists.

Tragically, some are using the terrible tragedy to justify their existing programs, slapping an "anti-terrorism" label on missile defense and military budget increases. We should be big enough and bold enough to redefine finally and thoroughly what we mean by national security, to suspend divisive debates, to compromise internally so we can act decisively against the real and present dangers.


Joseph Cirincione is Director of the Non-Proliferation Project at the Carnegie Endowment for International Peace in Washington, D.C.

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