Tactical Devices Still Present Major Threat

Thousands of these arms are scattered throughout Russia, in the form of missile warheads, artillery shells, aircraft bombs and land mines. Because of the security weaknesses of Russia's decaying military infrastructure, these explosives are more likely to fall into the hands of terrorists or "rogue" states than those of any other country, say Western government officials and independent experts.

U.S. officials acknowledge that such tactical weapons pose a proliferation danger, and they discussed safeguards with Russian leaders in the talks that led to the treaty signed Friday. But analysts say the Americans were reluctant to push too hard, for fear of endangering the agreement to reduce by two-thirds the number of nuclear warheads deployed by the two nations.

Critics maintain this was a mistake, considering that the Sept. 11 attacks drove home the message that terrorists and rogue regimes might pose a greater risk than a long-range strike by a former Cold War adversary.

"In the post-9/11 world, these are the [weapons] that pose the greatest threat," said Alistair Millar, of the Fourth Freedom Forum, an arms control group in Washington. "That's a pretty severe omission."

Some prominent centrist and conservative figures have joined liberal arms-control advocates in arguing that the United States should be pushing for greater controls on tactical weapons.

Former Sen. Sam Nunn (D-Ga.), former Clinton administration Defense Secretary William J. Perry and retired Air Force Gen. Eugene E. Habiger, former commander of U.S. strategic nuclear forces, argued this week that top priority should be given to an accurate accounting of both countries' tactical nuclear arsenals.

"These are the nuclear weapons most attractive to terrorists--even more attractive to them than [radioactive bomb-making] material, and much more portable than strategic warheads," the three wrote in an opinion page article in the Washington Post.

Tactical nuclear weapons are generally defined as those designed for use against military targets on the battlefield. Strategic nuclear weapons are larger long-range weapons that are designed for use against cities or strategic nuclear missile forces.