"Preemption" is supposed to be the new slur. Its use now conjures up all sorts of Dr. Strangelove images to denigrate the present "trigger-happy" Bush administration. Partly the hysteria is due to the invasion of Iraq. Or perhaps the venom of the Left comes from recent disclosures that, in the post-9/11 era, the United States has publicly proclaimed it may strike terrorists and their sponsors — or indeed rogue nations who have the history, capability, and desire to obtain frightening weapons — before they strike us.But instead of a rational discussion about the wisdom and feasibility of that logical policy,...