President Bush did not mention it, but the arms control approach he presented Tuesday would undo one of the signal accomplishments of his father's administration: the ban on multiple-warhead missiles based on land.
Throughout the Cold War, it was widely assumed that such missiles were particularly destabilizing weapons. NATO was so worried about the Soviet Union's 10-warhead SS-18 that its code name for the missile was Satan, and Reagan administration hard-liners warned darkly that it would be useful for a surprise strike.
START II, a treaty signed in 1993 by the first Bush administration, banned land-based MIRVs, as the multiple-warhead missiles are known, a move that arms control specialists agreed made the nuclear balance more stable.
But the new Bush administration does not see Russia as a nuclear adversary and, officials say, has no interest in rescuing START II, which has never taken effect because of disputes about conditions attached by both the U.S. Congress and the Russian Parliament.
By omitting any mention of START II, the administration signaled that its strategy is to leapfrog over that agreement and move to a more streamlined arrangement in which the United States and Russia separately announce plans for deep cuts.
That means that START II and its provisions, including the ban on land-based missiles with multiple warheads, becomes an artifact of history, one policymaker said.
Administration officials say there is no need to perpetuate a ban hammered out during the tense days of the Cold War. Much of the new U.S. deterrent will be based on submarines, making it almost invulnerable to surprise attack.
But some arms control proponents are critical.
"It means abandoning one of the most hard-fought gains for U.S. national security," said Joseph Cirincione, a senior associate at the Carnegie Endowment for International Peace. "Multiple-warhead missiles are dangerous weapons and will remain in the Russian arsenal long after Putin is gone."
The new administration stance is part of a broad rethinking about arms control that has led the administration to announce reductions in its nuclear arsenal.
While Bush administration officials insist that their review was driven by a hard-headed look at nuclear requirements, no one was oblivious to the foreign policy implications.
A public pledge to slash the number of nuclear arms, officials understood, would help make the case to the Russians, as well as to other Europeans, that the administration's plan to build a missile defense was not part of a drive for strategic dominance.
It might even make the Russians more willing to go along with the administration's plans to conduct antimissile tests. These were not permitted by the 1972 Anti-Ballistic Missile Treaty, still a bone of contention.
Still, some of the most important shifts had nothing to do with numbers. In addition to quietly walking away from START II's ban on land-based multiple warhead missiles, the Bush administration says there is no need for formal treaties on offensive nuclear arms.
Instead, the administration's approach is to spell out the reductions the United States is planning while the Russians do the same. The reductions would be verified by provisions for on-site monitoring carried over from START I, signed in 1991.
Administration officials say that dispensing with treaties will enable them to avoid the lengthy process it takes to negotiate them. But critics say it will also leave the two sides without a solid legal undertaking on nuclear arms that would outlast the Bush and Putin administrations.
Putin was skeptical as well, saying he was prepared to codify all of the understandings between the United States and the Russians "in treaty form."
Bush signaled that he did not think that a formal treaty was necessary, but added he would be willing to make a less formal commitment.