The Pentagon needs two successful missile interceptions to be confident that its missile defense system will work. It has one under its belt, but the second test missed by 100m due to a leak in the tubing that cooled the seeker. The third test is scheduled for June (but is expected to slip into July) and the fourth is set for October. The Pentagon wants a decision to deploy the system made in June but expects that President Clinton will announce it in November, but only if one of the next two tests is a success. It's not as simple, however, as getting one hit in two more tries. The third test will incorporate a new system designed to allow the interceptor to communicate with the ground tracking stations. If that system fails, the fourth test could be delayed several months as they dismantle the entire fourth kill vehicle to replace the communications unit. Plans are to deploy 20 interceptors in 2005, eventually reaching 200-250 weapons. Secret tactical plans leaked by the Bulletin of the Atomic Scientists show that four interceptors will be fired at each incoming missile, meaning that the entire system will be good against only 60 or so incoming missiles. The US has told the Russians this, since they have more than 60 missiles and the US wants them to agree that the defense shield is no threat to their own nuclear deterrent. The Russians are convinced, however, that the US would field many more interceptors and would fire only one or two at each incoming missile, meaning that the US could intimidate or even attack Russia without fear of retaliation.--Stephen V Cole