Last night's decisive House vote against spending more money on the MX missile marks the most significant attempt by Congress in 13 years to redirect the course of a nuclear weapon the president had deemed vital to the national defense.
The precedent for yesterday's action was the congressional debate during the late 1960s over appropriating money two presidents had requested for an anti-ballistic-missile system to defend against Soviet attack.
President Nixon in 1969, like President Reagan in 1981, changed the deployment scheme he inherited from his predecessor in an attempt to win over public support. As support eroded and the Senate rejected by only a 50-to-50 vote a 1969 amendment to stop deployment of the Safeguard ABM, the project was never completed.
It is too early to tell whether Reagan's scaling down of President Carter's more ambitious MX deployment scheme will similarly fail to overcome the opposition to this nuclear weapon. While yesterday's vote sends a dramatic signal to the president, it is far from the end of the congressional action on the missile.
If the past is any guide, contrary to what the White House has argued, a setback on the MX missile may push Reagan toward new arms control agreement with the Soviet Union.
Nixon negotiated out of his ABM dilemma by signing a 1972 agreement with the Soviets limiting each side to deployment of ABM missiles in only two locations: the national capital and one intercontinental ballistic missile (ICBM) site. The two superpowers agreed in 1974 to shrink ABM deployment further to one ICBM site in each country, with the United States choosing Grand Forks, N.D.
Since the Soviets publicly threatened on Tuesday to put big missiles of its own in a closely spaced Dense Pack formation if the United States does so with MX, Reagan, like Nixon, conceivably could turn to "we won't if you won't" negotiations. However, the Reagan administration has argued that Soviet missiles already can knock out our land missiles but we cannot do the same thing to theirs.
Deploying MX so closely together in the Dense Pack mode that attacking warheads exploding over them would blow each other up, Air Force Brig. Gen. J. P. McCarthy told the House Appropriations Committee in recently released secret testimony, would "put Soviet hard targets at risk, which is the principal reason why we need the MX missile."
Last night's vote is likely to force an agonizing reappraisal by the president, Congress, Pentagon and public, and may mark a sea change in American nuclear policy.