"We don't see it as a substitute for the limited National Missile Defense system, but something that will be in addition to it," Cohen said of the Russian proposal after talks with President Vladimir Putin and Defense Minister Igor Sergeyev.
Putin has proposed that the U.S., NATO and Russia develop a joint defense against missiles from so-called rogue nations, such as North Korea, as an alternative to the U.S. plan to deploy the NMD.
Russia adamantly opposes the NMD, saying it would undermine the foundation of the Anti-Ballistic Missile Treaty.
Sergeyev wouldn't offer any technical details of the Kremlin's proposal. Cohen said that Russia proposes a system to be deployed near rogue states that would destroy enemy missiles shortly after liftoff.
The U.S. proposal is for a system that could also destroy missiles while they are in space or descending toward their target.
Cohen said Tuesday that the Russian proposal deserves a close study, but added that it raises numerous technical and political problems. "A great deal needs to be done in terms of the technology involved in such a boost-stage system, and the practical implications of this," Cohen said.
Along with the technical difficulty of tracking and quickly knocking down an enemy missile, it remains unclear where such system would be deployed, how it would be controlled and manned and who would make the launch decisions, Cohen said.
During the talks, Cohen again tried - and failed - to soften Moscow's opposition to the U.S. desire to amend the 1972 ABM treaty to make way for the NMD.
Putin underlined the importance of avoiding "any steps that could undermine the ABM treaty, and, accordingly, the strategic stability in the world," the Kremlin said in a statement.
"Russia doesn't see an opportunity to modify this treaty without violating it," Sergeyev told reporters. "And walking out of the ABM Treaty would trigger a new arms race."
Putin and President Clinton failed to reach agreement on the ABM during their Moscow summit earlier this month, and Putin has warned that Moscow would pull out of all nuclear arms agreements if the United States breaches the ABM treaty.
Russia says the NMD could be quickly expanded to be able to take out Russian missiles, making them useless and thus upsetting the strategic balance.
Cohen tried to convince the Russian officials that the NMD system needs to be quickly deployed in the face of expectations that North Korea will have intercontinental-range missiles by 2005.
But Sergeyev responded that Russia doesn't consider North Korea a threat.
"We disagree on our assessment of the level of the threat," he said. "e see it as a possible, potential, virtual threat, and Americans see it as an already present threat."
As an alternative to NMD, Sergeyev also proposed joint efforts to set up a "political umbrella" to avert missile threats. He offered no specifics.
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