U.S. Homeland Security officials are coming under increasing political pressure to overhaul, if not eliminate, their color-coded terror alerts as concern mounts that the current system has become so dysfunctional that it may actually be increasing the country's vulnerability to attack.

Describing last month's Code Orange alert as a "useless" warning for the public, Rep. Chris Cox, chairman of the House Homeland Security Committee, told NEWSWEEK that he now wants extensive changes in the system that go well beyond the adjustments that are being publicly contemplated by the Bush administration. "The more fundamental question is whether the system can work at all," said Cox, a California Republican, who has raised the matter in recent weeks with top counterterrorism officials.

The concerns expressed by leading members of Congress-including Cox and Rep. Jim Turner, the ranking Democrat on the Homeland Security panel-have been heightened by some intelligence-community analysis suggesting that the color-coded public alerts may have perverse effects opposite to what the government intends. The public ratcheting up of the threat level may actually alert Al Qaeda operatives to measures that law-enforcement and security officials are taking to thwart attacks-and might therefore prompt terrorists to defer attacks that were conceivably in the planning stages, some intelligence analysts say.

By the same token, the public downgrading such as was announced last week-when Homeland Security scrapped the "Orange" alert for the current lower-level Yellow-arguably puts terrorists on notice that defensive measures have been reduced, and thereby might prod them to strike. "We might actually be increasing the threat to American when we reduce the threat level," said Cox.

Although in one sense blindingly obvious, this intelligence analysis is buttressed by a rethinking of the core premises behind the administration's decision-making system on terror alerts. Consider Secretary of Homeland Security Tom Ridge's Dec. 21 announcement of the Code Orange alert.

The move was prompted by two main developments: one was alarming new intelligence, some of it apparently coming from a new overseas human source, that provided information that Al Qaeda might seek to hijack French, Mexican or British airliners over the Christmas holidays. Officials even received information about specific flight numbers, leading the United States and foreign governments to take the extraordinary step of canceling some flights and directing that F-16 jets accompany others over U.S. territory.