From the Summary: "In recent years, the debate over National Missile Defense (NMD) has focused on how best, and how quickly, to develop and deploy a system to protect the United States against a limited ballistic missile threat- either an accidental or unauthorized launch from Russia or China or a deliberate attack from a rogue state. The Clinton Administration is pursuing what it calls a '3 plus 3' strategy- the goal is to develop NMD technology over the three years through 2000 sufficiently to allow a system to be deployed three years later, by 2003, if a decision is made to do so. If a decision to deploy is deferred, development would continue. Many missile defense advocates in Congress, however, want to set a date for deploying a nationwide defense. Key issues in the debate include how quickly rogue nations might acquire long-range missiles, whether advances in technology warrant deferring a decision to deploy, whether an initial deployment should be followed by a more extensive system, cost, and the implications of a deployment decision for the Anti-Ballistic Missile (ABM) Treaty and for negotiating further limits on strategic offensive weapons. Faced with the prospect of a Presidential veto, Congress has not set a deployment date in annual defense authorization or appropriations bills. Instead, Congress has considered freestanding bills to establish NMD policy- recently the Senate took up the American Missile Protection Act of 1998, S. 1873, but a cloture vote failed on May 13."
CRS Report for Congress, 97-862