While Russia amended its military doctrine years ago to allow for the possibility of using nuclear weapons first in retaliation to a non-nuclear attack, the statement by Deputy Prime Minister Dmitry Rogozin reflected Moscow's concern about prospective U.S. conventional weapons.
Weapons that have been developed in the United States under the so-called "prompt global strike" program would be capable of striking targets anywhere in the world in as little as an hour with deadly precision. Russia, which has lagged far behind in developing such weapons, has described them as destabilizing.
Without naming the U.S., Rogozin told lawmakers in comments carried by Russian news agencies said that those who "experiment with non-nuclear strategic weapons" should remember that "if we come under attack, we will undoubtedly use nuclear weapons in certain situations to defend our territory and state interests."
He said that it should discourage any potential aggressor.
"We have never underestimated the role of nuclear weapons ... as a 'great equalizer,'" Rogozin said.
Asked for reaction, an official at North Atlantic Treaty Organization headquarters in Brussels said, "NATO has stated repeatedly that it does not view Russia as an adversary. Last year at the Chicago Summit, NATO leaders reiterated their desire to see a true strategic partnership between NATO and Russia. NATO is committed to the principles laid out in the Founding Act of the NATO-Russia Council, and works productively with Russia across a range of issues of common concern."
The Russian doctrine mirrors the American strategy during the Cold War, when the U.S. would not rule out using nuclear weapons first, because it feared it might have to do so in response to overwhelming conventional attack on western Europe by Soviet forces.
Rogozin said that Russia is working on developing its own version of the "prompt global strike" weapons, but wouldn't give any details.
The U.S. plans included modifying some of the existing nuclear-armed missiles to carry conventional warheads as well as designing new vehicles capable of traveling at least five times the speed of sound.
Russian officials said that such U.S. weapons wouldn't fall under any restrictions but would have combat efficiency comparable to nuclear weapons, and thus should be included in any prospective nuclear arms reduction talks.
Russian suspicions about the U.S. intentions have aggravated tensions caused by a dispute over the U.S.-led NATO missile defense program, which Moscow sees as a threat to its nuclear deterrent.
Russia has increasingly relied on nuclear weapons in its military strategy to compensate for a post-Soviet decline in its conventional forces. The nation's military doctrine says it may use nuclear weapons to counter a nuclear attack on Russia or an ally, or a large-scale conventional attack that threatens Russia's existence.
Rogozin's comment comes a day after President Vladimir Putin pledged to continue an ambitious weapons modernization program and to expand Russia's military presence in the Arctic region. Putin has pointed at the U.S. navy presence in the Arctic Ocean as one of the reasons behind the buildup, saying that Russia is concerned because it takes U.S. missiles just 15 to 16 minutes to reach Moscow from a submarine in the Barents Sea region.
The statements reflected the current strain in Russian-U.S. relations, which have been hurt by disputes over the U.S.-led missile shield, Russia's human rights record and, most recently, differences over Ukraine.
NATO's official defense posture: http://www.nato.int/cps/en/natolive/official_texts_87597.htm?mode=pressrelease ).
AP correspondent John-Thor Dahlburg contributed from Brussels.
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