In a rare joint appearance on the op-ed pages of the New York Times, Warren Christopher, the Secretary of State and the Defense Secretary, William Perry, said that the bill, originating in the Republicans' "Contract with America" manifesto, would undermine national security and the President's authority over foreign affairs.
The administration's deep hostility to the measure, which, if implemented, would have devastating consequences for United Nations peace-keeping operations, is well known.
But the public foray of Mr Christopher and Mr Perry is also a sign of the alarm among Washington's allies and of the apparent failure of an intense lobbying campaign on Capitol Hill to make Republican policy-makers change their minds.
The 1,000-word critique takes aim at three aspects of the legislation: the resurrection of plans for the rapid development of a "Star Wars" anti- ballistic missile system, the naming of specific European countries to be admitted to an enlarged Nato and prosposals that would free Washington from paying its share of the cost of UN peacekeeping.
The deployment of a new anti-missile defence system, Mr Christopher and Mr Perry said, would divert billions of dollars to a scheme that was not justified "by any existing threat to our national security". They defended theatre systems now under construction to deal with the threat of Scud- like missiles in the hands of "rogue regimes" like North Korea, Iran and Iraq.
Guaranteed and automatic enlargement of Nato, meanwhile, would be premature and dangerous. Today's "steady and deliberate" approach to enlargement gave European countries the incentive to consolidate reform. Drawing up a list of entrants could "discourage reformers in countries not on it and foster complacency in those that are."
Most worrying to the administration are the anti-UN provisions - music to the ears of the strong isolationist faction on Capitol Hill. They have been elaborated just as the US is subscribing to new peace-keeping ventures in Haiti and Angola.
The bill would require Washington to reduce peace-keeping payments on a dollar-for-dollar basis against spending on voluntary operations led by the US. This, Mr Christopher and Mr Perry said, would "effectively abrogate our treaty obligation to pay our share of peace-keeping missions agreed in the Security Council."
Where Washington led, other nations would follow. "It would end peace- keeping overnight." They objected to restrictions on placing US troops under a foreign commander, even a commander from a Nato ally, for UN operations, saying such a move would reduce the ability of the US to persuade the international community to act jointly against a common threat.