In today’s Washington Post, Fred Hiatt writes about a frightening report commissioned by the Nuclear Threat Initiative that says our response to the threat of nuclear terrorism has been dangerously inadequate: Ignoring The Unthinkable. (Hat tip: NC.)

If a terrorist were to detonate a 10-kiloton nuclear bomb in Grand Central Station, about half a million people would die immediately — roughly equivalent to the population of Washington, D.C. Much of Manhattan would be destroyed, and depending on the prevailing winds the rest of the island might have to be evacuated. Hundreds of thousands more would die of burns and exposure to radiation. The direct economic effects would surpass $1 trillion, or one-tenth of the nation’s annual economic output. Indirect effects — if, say, the terrorists threatened to destroy another city — would be much higher.

It is impossible to predict how U.S. social and political structures would change after such an attack. But if you posit, for a moment, sufficient normalcy to imagine a congressional hearing, you can also imagine questions, as after 9/11, about who had failed to “connect the dots,” and why.

In this case, however, such questions would be met by an astonishing response. Officials would have to acknowledge that the dots had been connected long before the attack; that both the danger and the means to eliminate it had been well understood; and that the president and Congress had failed to do what was necessary.