WASHINGTON, June 24, 2001 
An internal Defense Department study concluded last year that testing on the national missile defense program was behind schedule and unrealistic and had suffered too many failures to justify deploying the system in 2005, a year after the Bush administration is considering deploying one.

The August 2000 report from the Pentagon's Office of Operational Test and Evaluation, only recently released to Congress, offers new details about problems the Pentagon has encountered in developing antimissile technology. And it raises questions about how quickly an effective system can be made operational.

The Pentagon is studying proposals to deploy a limited system, but one that would violate the 1972 Antiballistic Missile Treaty, as soon as 2004. In recent weeks, Secretary of Defense Donald H. Rumsfeld has indicated a willingness to deploy a system before tests have been completed if an attack seems imminent.

But as an example of unrealistic testing, the report cited an October 1999 test in which a Global Positioning System inside a mock warhead helped guide an intercept missile toward a target over the Pacific. That test was successful, but two more recent flight tests failed.

None of those tests used the kinds of sophisticated decoys that a real ballistic missile would use to confuse an antimissile system, the report said. Instead, the decoy in each test was a large balloon that did not look like a warhead and that the kill vehicle's sensors could easily distinguish from the target.

The report also asserted that the Pentagon had not even scheduled a test involving multiple targets, the likely situation in an attack. And it found software problems with a training simulator that made it appear as if twice as many warheads had been fired at the United States as had been intended in a 1999 exercise.

The simulator then fired interceptors at those "phantom tracks," and operators were unable to override it, the report said.

The report, which President Bill Clinton read just before deferring initial construction on a missile system last September, acknowledged that the program was still in its early stages and was progressing well on some fronts. But it concluded that unless testing was significantly accelerated, at significantly higher cost, the program would not be ready for use against real attacks for several years.

"Deployment means the fielding of an operational system with some military utility which is effective under realistic combat conditions," the report states. "Such a capability is yet to be shown to be practicable for NMD," or national missile defense.

Officials with the Pentagon's Ballistic Missile Defense Organization disputed parts of the report, saying that the Global Positioning System used in the 1999 test did not guide the kill vehicle to the target. They also contended that the simulator did not fire at "phantom" missiles.

They acknowledged software problems with the simulator but said those flaws had been fixed. And they asserted that future tests, perhaps starting next year, would involve tougher situations, including more sophisticated decoys, multiple warheads and different trajectories.

"We fully intend to stress the system to its maximum capability," Lt. Col. Rick Lehner, a spokesman for the organization, said.

But skeptics of missile defense said the report clearly showed that even the most advanced antimissile technology needed years of testing to work out unforeseen bugs. Without such testing, they warned, the system would be at best ineffective and at worst dangerous.

"The problems have been different each time," said Philip E. Coyle, a former assistant secretary of defense and director of operational testing, who helped write the report. "In each case, the thing that failed was something you'd have liked to have taken for granted. It just shows how hard this stuff is."

The report, which members of Congress plan to make public this week, is expected to fuel a contentious debate over how swiftly a missile system should be deployed and how much money should be spent developing one.

Mr. Rumsfeld has argued that the United States should deploy a system quickly to dissuade its rivals from trying to acquire ballistic missiles. He contends that no weapon system works perfectly and that a limited missile defense can be gradually improved and expanded.

During his recent trip to Europe, Mr. Rumsfeld gave NATO defense ministers a paper stating that the United States "will likely deploy test assets to provide rudimentary defenses to deal with emerging threats."

The Pentagon has also been studying a proposal from Boeing, the lead contractor on a missile defense system, to install a basic antimissile system involving five interceptors in Alaska by 2004. The system, which would violate the ABM treaty, would use existing radar and rockets as interim technology until more advanced systems were ready.

But in an appearance by Mr. Rumsfeld on Capitol Hill on Thursday, Democrats vigorously questioned those proposals and expressed strong reservations about speeding up a system they said remained unproven.

The Democrats have also raised concerns about the Bush administration's threat to withdraw from the ABM treaty if Russia refuses to amend it. Mr. Bush has argued that the treaty prevents the United States from testing promising technologies, like sea-based or airborne weapons.

Pentagon officials have said none of the tests planned through 2002 would violate the treaty. But aides to Mr. Rumsfeld are restructuring that schedule, possibly to add tests in a few months that could violate the treaty's prohibitions, a senior administration official said.

Though the Office of Operational Test and Evaluation's report is nearly a year old and does not contain classified information, Pentagon officials asked the House Government Reform Committee, which obtained a copy, not to release it publicly, in part because they said it contained inaccuracies.

But Democrats contend that the Defense Department does not want damaging new details about its testing program to be released just as Mr. Rumsfeld is preparing to ask Congress to increase financing for missile defense research and development by $2.2 billion.

"In the mad rush to deploy, I suspect that any bad news is not what they want Congress to be debating or the public to be aware of," said Representative John F. Tierney, Democrat of Massachusetts, who has been a critic of missile defense. "This has huge ramifications. It should be part of the public dialogue and part of a very sober assessment of the system."