Watered down and designed to offend no one, critics say, high school textbooks' treatment of Sept. 11, 2001, show all too well the difficulties of depicting an event teetering between history and the news.

The rule of thumb among educators is that most editions of history textbooks last five to 10 years before a school system replaces them. By that formula, it's reasonable to assume that plenty of students are studying from books that deal with the events of Sept. 11 and its five-year aftermath. The significance of this is that an event's treatment in the news changes daily, but a textbook's handling of it can become the interpretation of record for a generation.

But how to write about something that hasn't reached its conclusion? Or about something so politically and culturally charged that any interpretation is bound to meet objections?

"To be honest, I would say that writing about 9/11 isn't all that different from other emotionally and politically charged events, such as the Civil War, Pearl Harbor, the Vietnam War and so forth," Lizabeth Cohen says in an e-mail.

One of the authors of the high school-level "The Brief American Pageant," Cohen acknowledges that it is challenging to write about something everyone still remembers vividly. But even events from the distant past still stir strong opinions, she says.

"Serious historians routinely encounter conflicting interpretations of events, so you always have to pick your way through a minefield of other accounts."

But textbook writers don't negotiate their way through the minefield of controversy, critics say, so much as they avoid it altogether in an effort to have their books adopted by as many school districts as possible.

Sept. 11 "tends to be written about in a way that will not elicit controversy or get publishers in trouble," says Gilbert Sewell, director of the American Textbook Council. "The result is a kind of detachment that fails to convey the significance of the political."

Sewell's group, a nonprofit based in New York, charges that history books since Sept. 11 have ignored "the global ambitions of militant Islam." It makes particular note of the fact that some books avoid the term "jihad" altogether.

James W. Loewen, author of "Lies My Teacher Told Me: Everything Your High School History Textbook Got Wrong," says the history books' treatment of Sept. 11 is in step with everything else wrong with textbooks: It's boring.

"One of the reasons that American history textbooks are so boring is that they don't really have a storyline," he says.

It's all facts and no analysis. "The books don't treat the question 'Why?' " he says. "For example, why did the terrorists attack the U.S. — why not Sweden? That's a reasonable question."

The main cause of their blandness, he says, is that textbooks tend to be written by committee. The authors whose names are on the cover often have no hand in the updated editions.

Randy Roberts, a professor of history at Purdue University, says neither he nor his co-authors encountered any pressure from their publishers, Prentice Hall, regarding the content of their textbook "United States History."

"I can say categorically that there was absolutely no political pressure," he said. "Certainly, we decided what coverage we wanted, but in terms of pressure, political or otherwise, there was zero."

The upside of teaching something so recent is that teachers have no shortage of resources to supplement the textbooks. Video, newspapers, material from the Internet are all easily accessible to teachers. But it's a long way before there are any widely accepted standards as to how to approach the topic in the classroom.

"The truth is, we're just beginning to see it as anything other than a momentously sad event," says Tom Moore, supervisor for social studies at Conard High School and Sedgwick Middle School in West Hartford.

Moore says he has spent part of his summer updating curriculum regarding Sept. 11. Because the impact of that day is still unfolding, he says, teachers can't rely too heavily on books.

"As a history teacher, you have to read two newspapers a day," he says. "I feel like I'm Tom Brokaw to the kids."