I checked all of the signers from the University of California, Santa Barbara, where I was a graduate student some 30+ years ago. There were six names listed.
Two of them are not listed among the faculty on the USCB History Department's website.
Of the four who are listed, two list their specialties as "U.S. Women's History", one is listed as a specialist in "U.S. Public Policy" and the other is listed as a "U.S. Labor" historian. Not one of them describes a specialty in European history, Middle Eastern, Asian or African history.
The department's website lists 9 historians whom I knew as a graduate student, eminent men in European, American, African and Asian history. Many of those men are liberals, one was (is?) an avowed socialist and historian of socialism. He did not sign, nor did any of the eminent sernior faculty sign that absurd statement.
What this means, is that it the "historians" who signed this statement are those whose professional interests have not lead them to study any of the significant events in the history of Western Civilization that might give them any perspective in the matter of the coming War with Iraq. Indeed, there opinions are no more valuable than any lay persons.