FOR THE PAST three months, Pentagon officials have veiled an essential aspect of the 'war on terrorism': civilian casualties in Afghanistan. Blocking access to information about the human costs of U.S. bombing -- and its consequences -- might create a dangerous future for Americans.

Such restrictions keep us from understanding how the rest of the world views the war, and why it might provoke future attacks on the United States. They may also breed complacency, ignorance and national insecurity.

Measures taken by military officials obscure information about the effects of U.S. bombing.

For example, since Oct. 11, the Pentagon has purchased exclusive rights to all satellite images from Space Imaging, a U.S. company that produces accurate pictures that might allow independent media to survey bomb damage.

In addition, U.S. bombs destroyed Al-Jazeera's television station in Kabul in October. The Qatar-based independent network reaches much of the Arab world and frequently broadcasts images from Afghanistan.

Official acknowledgment of civilian deaths has been minimal.

Descriptions of heavily bombed frontline positions never mention that they sometimes traverse densely populated neighborhoods. Frequently, officials claim that civilian deaths 'cannot be independently confirmed.'

Yet, according to a recent report by Professor Marc Herold, an economist at the University of New Hampshire, the number of Afghan civilians killed by American bombs has surpassed casualties from Sept. 11.

Herold's report -- the first independent survey of its kind -- claims that 3,767 civilian deaths were caused by U.S. bombing between Oct. 7 and Dec. 10. Not included are indirect deaths caused by land mines, lack of water, food or medicine.

The data, drawn from independent news sources and first-hand accounts, include: dates, locations, types of munitions used and sources. Much of it is based upon mainstream British, French and Indian press agencies such as the BBC and The India Times.

While respected news agencies abroad have reviewed Herold's report, the American media have largely ignored it. Only a few journals, Internet sites and the radio program 'Democracy Now!' have analyzed it.

Why have the U.S. media missed the story?

Part of the explanation may be related to the industry itself. Recent mergers between media corporations have homogenized news, especially television news. AOL/Time Warner, Viacom, News Corporation, Disney and GE own CNN, CBS News, Fox News, ABC News and NBC, respectively.

Many Americans rely exclusively upon this cartel for information on the 'war on terrorism,' which is presented more as entertainment than news.

Broadcasts include repetitive accounts of the search for Osama bin Laden, trivia about weapons, war images that resemble video games and footage of cheerful Afghans trimming their beards and playing music.

These pictures are punctuated by angry pundits and politicians who reduce complex events to simplified formulas ('good versus evil') using language reminiscent of Hollywood Westerns ('dead or alive').

Whether such misinformation stems from Pentagon pressure, fear of offending advertisers or shabby journalism is largely irrelevant. The effect is the same:

Warfare is presented as light entertainment.

While American viewers remain oblivious, Europeans, Asians and others have access to information about the catastrophic effects of U.S. bombing. They have seen images of dead and wounded civilians and the many widows, widowers and orphans created by Operation Enduring Freedom.

Many are convinced that this is a U.S. crusade against Islam, and with each passing week, violent 'blowback' -- the CIA's term for unintended foreign policy consequences -- appears more likely.

Ignorance may be dangerous in the current climate.

Murky official statements and a distracted mass media deny us information which might help prevent future attacks.

George Orwell once noted that in free societies, censorship is more sophisticated and thorough than in dictatorships because 'unpopular ideas can be silenced, and inconvenient facts kept dark, without any need for an official ban.'

But keeping Americans in the dark about inconvenient facts in Afghanistan is reckless at best, and potentially dangerous.

Civilian deaths should be openly acknowledged by the Pentagon and reported by the mass media if we wish to minimize the possibility of future attacks on American soil.