WASHINGTON -- The Pentagon, which once bragged that its Patriot missile destroyed every Iraqi Scud targeted during the Persian Gulf war, has hard evidence that only four of 47 Scuds were obliterated, congressional investigators reported yesterday.
After the war, the Patriot's boosters cited its near-perfect performance to justify building a costly "star wars" system designed to protect the United States against missile attack. Since then, the Patriot's effectiveness has been steadily downgraded.
The latest investigation shows that the Patriots destroyed only 9 percent of the targeted Scuds, said aides to Rep. John Conyers Jr., D-Mich., chairman of the House Government Operations Committee and a persistent Patriot critic.
Because the Pentagon has been so eager to use the Patriot as evidence that the multibillion-dollar star wars program would work, have demanded proof critics over the past year that the Patriot worked as billed.
But, as a new General Accounting Office report makes clear, the Pentagon's estimate of each missile's performance was, at best, flimsy.
Many assessments were made months after the war, consisting of eyewitness accounts that were "often unverified and sometimes contradictory" and studies of Scud impact sites where "the craters had often been filled and missile debris removed."
"We have watched the claims for this missile drop from 100 percent during the war to 96 percent in official statements to Congress, to 80, 70, 52, 25, and now we're under 10 percent and dropping," Mr. Conyers said.
The Patriots' dwindling performance record has weakened Capitol Hill support for star wars, said an aide to a House Democrat who favors the anti-missile plan.
Congress is expected to slash the Bush administration's $5.4 billion request for star wars in 1993 to $3.8 billion -- a 30 percent cut -- in the defense bill being worked out by House and Senate negotiators, he said.
Pentagon spokesman Pete Williams did not quarrel with the new figures on the Patriot's performance. "We gave the best assessment we had at the time," he said. "There was a lot of confusion about how effective Patriot was."
Mr. Williams noted that the Patriot was designed to protect only a small area from aircraft attack and that the Army stretched its capabilities in trying to defend larger areas against the smaller and faster Scuds. "It was intended to shoot down something that's a lot bigger and flies a lot slower," he said.
The ground-based Patriots are designed to explode when their fuses detect the presence of the target missile. If they explode close enough, the enemy missile is destroyed, but if they detonate more than a few yards away, the incoming missile may only be deflected or may escape damage entirely.
Investigators found what they called firm evidence of Scud destruction in only a handful of cases: Scud warheads peppered with Patriot fragments, or computer tapes showing the disintegration of a Scud following a nearby Patriot explosion.
The Army counted as a kill a Patriot exploding near a Scud, even though the Patriot's top engineer told the GAO the missile's fuse is so sensitive it could be set off well outside the lethal range.
"The Patriot's fuse can sense its target and detonate at up to six times the required miss distance, resulting in an extremely low or no probability of kill," the report said. "However, the system would still record a kill."