Rejecting Pentagon plans to study the idea, Congress has voted to ban military spending this fiscal year on research into using nuclear-armed interceptors in the U.S. national missile defense program.
The language was included in the $355 billion fiscal 2003 defense appropriations bill, approved by Congress and sent last week to President George W. Bush, who is expected to approve the bill.
The bill specifically forbids using funds "for research, development, test, evaluation, procurement or deployment of nuclear-armed interceptors of a missile defense system."
Senate Republicans and Democrats expressed surprise earlier this year after The Washington Post reported six months ago that a Pentagon Defense Science Board task force, a panel of independent experts, planned to study this August the nuclear-armed interceptors as an option for the program's ground-launched, mid-course intercept component. At the time, Sen. Ted Stevens, R-Alaska, objected, saying Congress had not approved money for such a purpose.
Missile Defense Agency Director Lt. Gen. Ronald Kadish told a Senate hearing no money was being spent by his agency on the nuclear-tipped concept.
Separately from that agency, the Pentagon-funded Defense Science Board assembles civilian experts to study scientific, technical, manufacturing and other questions to advise the senior Pentagon leadership.
Critics have charged the current leading mid-course intercept approach, which relies on a direct hit, as fundamentally flawed because potential adversaries could easily configure their missile warheads with decoys and countermeasures to fool U.S. defenses.
Nuclear interceptors are seen as a way of knocking everything out, but critics of that approach have said it could also destroy commercial and military satellites the U.S. military also relies on heavily for defense.