The treaty's impact is dulled by no rules for a timetable or destruction of warheads.
While politically important, this week's US-Russian accord to remove thousands of nuclear warheads from operational deployment is unlikely to make the world a markedly safer place.
Experts say that the Bush administration deserves credit for simply achieving an agreement to scale back offensive nuclear weapons, while also moving ahead with missile defense breaking the inertia over US-Russian strategic arms reductions under Clinton's presidency.
"We did get there in a way that is a little more informal, a little more unilateral, but we did it," says a nuclear expert affiliated with the Pentagon.
The treaty, to be signed by President Bush and Russian President Vladimir Putin in Moscow next week, also marks a diplomatic success. "The significance is not so much in strategic terms, it's more in terms of the relationship we are building with Russia," says Robert Einhorn, a former US assistant secretary of State for nonproliferation.
Yet many experts agree that the treaty's broad rules and open-ended approach make it less meaningful as a curb on a possible nuclear catastrophe. "The treaty does not make us more secure. But it may make us less secure, because the real risk is about diverting and stealing nuclear weapons," says Ivo Daalder, a senior fellow at the Brookings Institution in Washington.
In terms of sheer numbers, experts agree that a marginal gain in safety will result if the United States and Russia each lower the number of deployed nuclear warheads from about 5,000 to 6,000 to between 1,700 and 2,200 by the year 2012. "The fewer nuclear weapons there are, the less chance of accidents and miscalculations," says Joseph Cirincione, a nuclear-proliferation expert at the Carnegie Endowment for International Peace here.