The failure of the latest test for the controversial US National Missile Defence (NMD) project has sown doubts about its future, doubts which President Clinton may resolve before he leaves office.
The President is now waiting for a report on the feasibility of the project before he decides whether to order deployment of a first phase of 20 interceptors based in Alaska by 2005 and a radar detection system against incoming missiles. The cost is estimated at $60 billion.
While the US says the NMD is aimed at protection against a possible missile attack from "rogue nations" such as North Korea, Iraq or Iran, both Russia and China have strongly opposed it while European allies of the US have expressed concern it could lead to an escalation of the nuclear arms race.
At the White House, the National Security Council spokes man, Mr P.J. Crowley, said that the failure "will have to be taken into account as we make a judgement on technical feasibility". The Republican presidential candidate, Governor George Bush, called the test failure a "disappointment", but said that pressing ahead with NMD would be a priority if he is elected next November.
US officials were embarrassed when the "kill vehicle" failed to separate from its booster rocket and go on to intercept a dummy warhead over the Pacific Ocean. A decoy balloon, launched with the dummy warhead from Vandenberg Air Force base in California, failed to inflate.
The interceptor rocket, fired 20 minutes later from Kwajalein Atoll 4,300 miles away in the central Pacific, apparently swerved off course as it approached the dummy warhead. It also failed to release the "kill vehicle", which was supposed to hunt down its target using highly sophisticated sensors while travelling at 15,000 miles an hour.
This was the third test of the system, which is designed by the Boeing and Raytheon aerospace companies. The second test also failed and the first was a partial failure. Another 16 are scheduled over the next five years to make the system more accurate. But military and scientific critics have predicted that it will be a costly failure and be unable to distinguish between incoming nuclear warheads and decoys.
Congress has already voted in favour of NMD but has left the decision on deployment of its first phase to the President. Such deployment would be seen by Russia as a breach of the 1972 Anti-Ballistic Missile treaty.
Mr Clinton has proposed amending the ABM in talks with President Putin of Russia, so far without success. Mr Putin has instead offered to work with the US and other countries in developing a new system to counter missile threats from North Korea.