WASHINGTON -- Russian President Boris N. Yeltsin is taking increasing control over the Soviet Union's strategic military forces, including "de facto" power to veto the use of nuclear weapons, U.S. officials and independent analysts said yesterday.
Mr. Yeltsin's growing influence, reflected in new high-level Soviet appointments and the weakening of Soviet central authority, suggests that the country's tight control over an estimated 27,000 nuclear warheads may actually be drawn even tighter, they said.
This would minimize the chance that nuclear weapons could be launched or fall into the wrong hands.
"There's a fairly complex structure in place, and recent changes only make us more confident, especially in terms of personalities," a senior Bush administration official said.
The system that controls and protects the vast Soviet nuclear arsenal has been "very strictly run by the Soviets, and I haven't heard any concerns expressed [in the administration] that this has changed for the worse," the official said.
Bruce G. Blair, an expert on Soviet military control at the Brookings Institution, called it "inevitable" that command authority would be transferred from the central government to Mr. Yeltsin because pro-Yeltsin generals have now become the Soviet defense minister, deputy defense minister and military chief of staff. These are all key links in the Soviet chain of command that must cooperate if a nuclear weapon is to be launched.
"The system is already a multitiered system of safeguards that require a collective act by top political and military officials" to launch a nuclear attack, Mr. Blair said. "By bringing Yeltsin in, you add another layer to make it a more collective political decision, as opposed to a political decision of the Soviet president alone."
He predicted that, in coming months, Mr. Yeltsin "will be given the essential nuclear codes, and he'll be tied into the communications net and receive the same notifications of [attack] warning that Gorbachev receives."
In Moscow yesterday, Russian Vice President Alexander Rutskoi called for a "double structure" of authority over the nuclear arsenal so that the Russian Republic could formally veto any decision to launch a nuclear strike. He proposed that the Soviet president could not use "global strategic weapons . . . without the consent of the president of Russia."
"This is done to avoid the situation that we have just had," he said.
During last week's failed coup, hard-liners seeking the ouster of Soviet President Mikhail S. Gorbachev wrested away control of the device containing nuclear weapons codes.
Soviet and U.S. officials have insisted, however, that there was never any danger of a nuclear confrontation or that Soviet nuclear safeguards were compromised.
"We did not believe there was any increase in the risk of the use of nuclear weapons during the coup," Defense Secretary Dick Cheney told NBC's "Meet the Press" on Sunday.
U.S. officials and analysts pointed out that no single person in the Soviet chain of command could actually unleash a nuclear attack because of an intricate system that requires the complicity of the Soviet military's general staff and the KGB, among others. They added that Soviet authorities, concerned by mounting ethnic and political unrest in the breakaway republics, spent much of the last two years improving the security of their nuclear arsenal to keep warheads from falling prey to separatist terrorists or other extremists.
The Soviets have required a safety lock system, called permissive action links, throughout their arsenal. They continue to store most nuclear warheads separately from the missiles that would deliver them, the experts said. In addition, strategic-weapons sites are guarded by special troops and controlled by the KGB, whose ranks were as divided as the military's during the coup, they said.
Lately, the KGB is being moved under army command.
Jack Mendelsohn, a former U.S. arms negotiator, said he expected current trends to result in an even stricter "command and control" system governing Soviet strategic military forces. "The football [containing Soviet nuclear codes] still remains in Moscow and, with few exceptions,the strategic nuclear forces remain in the Russian Republic," he said.
The Soviets began removing tactical nuclear weapons from volatile Baltic and southern republics in early 1990, withdrawing them to the Russian Republic, U.S. officials said. At Soviet request, the recently signed Strategic Arms Reduction Treaty includes a provision allowing the Soviets to relocate SS-18 intercontinental ballistic missiles from the Kazakhstan Republic in Central Asia, presumably back to the Russian Republic.