In the news business, a false story sometimes takes root in the public thinking and the truth has a hard time catching up. For example, the latest test of one of President Bush’s favorite projects, the National Missile Defense system, was hailed as a brilliant success. Television news broadcasts showed test staffers cheering as an intercontinental ballistic missile soared high over the Pacific Ocean, ignored an accompanying decoy, and homed in to “kill” a simulated enemy missile that had been launched from the Marshall Islands.

The truth now is coming out. That July 14 test, like previous tests, was rigged. The target warhead contained a beacon that sent out a stream of radio signals to help the attacking missile tell the difference between the target and the decoy and find its way to the “kill.” The Pentagon concealed news of the beacon but eventually admitted it, arguing that it was necessary because a key radar device had not yet been developed.

What’s more, says Thomas A. Halsted, former director of public affairs for the U.S. Arms Control and Disarmament Agency, writing in The Los Angeles Times, the collision of interceptor and target produced a cloud of debris that overwhelmed the Raytheon X-band radar that is the brains of the national missile defense system. Mr. Halsted writes: “The radar would thus have been incapable of tracking any additional targets or discriminating between them and any decoys, an essential task in any real attack scenario. This is a major flaw. A missile defense system that can find and destroy only one target is no defense at all.”

The existence of the beacon was first disclosed in a report by Philip E. Coyle, former director of Operational Test and Evaluation at the Pentagon, made public in June. It was reported in the journal Defense Week and in a Reuters dispatch, but the news escaped the notice of network television news, The Associated Press and most newspapers. For most newspaper readers, the first word about the beacon appeared Aug. 21 in the Doonesbury cartoon by Garry Trudeau.

The defense contractors knew about the rigged test. The Pentagon knew about it. The defense committees of the House and Senate knew about it. So did a few civilian specialists in national security matters. Only the American public was left in the dark for four weeks, bamboozled by people who want to make it look easy to “hit a bullet with a bullet.”