YOU DON’T HAVE TO FOLLOW the debate over war against Iraq for long without noticing the recurrence of a certain term: “clear and present danger.” In fact, if you do a Nexis search for the past six months for “clear and present danger” and “Iraq,” you’ll find more than 600 mentions. Do the same search on Google and you’ll get more than 4,600.

This week, as the congressional debate over a resolution authorizing war goes full throttle, it will feature multiple references to “clear and present danger.” Iraq is a clear and present danger, the argument in broad terms will go, and something must be done to counter it, with war a possibility. In opposition, it will be said that Iraq is not a clear and present danger. And so there is no need to go to war.