Russia has threatened to withdraw from the Intermediate-Range Nuclear Forces treaty or INF. In this report from Washington, VOA Senior Correspondent Andre de Nesnera looks at the reasons for Moscow's decision.

The INF treaty was signed in December 1987 by U.S. President Ronald Reagan and his Soviet counterpart, Mikhail Gorbachev. It entered into force in June 1988.

Steve Andreasen, former arms control expert on the National Security Council (1993-2001), says the treaty did away with a whole class of missiles.

"The Intermediate-Range Nuclear Forces Treaty basically eliminated for the United States and then-Soviet Union, now Russia, all nuclear and conventional ground-launched ballistic and cruise missiles in an intermediate-range band, that is 500 to 5,500 kilometers. And in fact, Washington and Moscow no longer deploy those missiles," he said.

By May 1991, all intermediate range missiles were eliminated. Those included on the U.S. side the Pershing-2 and on the Soviet side, the SS-20. A total of 2,692 missiles were destroyed: 846 on the U.S. side, 1,846 on the Soviet side. The treaty also prohibited the production of such missiles.

But now Russian officials, including president Vladimir Putin, have questioned whether abiding by the INF treaty is in Moscow's security interest.

Andreasen says one reason the Russians are reassessing their commitment to the 1987 treaty, is that a number of countries in Russia's neighborhood have INF-range systems.

"First of all North Korea, India, Iran, Pakistan, Israel, all of whom are in varying degrees of how should I say, proximity to the Russian border," he added. "As I say, the INF treaty which was a treaty that eliminated U.S., Soviet, then Russian intermediate-range systems, and they were nuclear or conventional, did not, in effect, put a global prohibition on those systems. And in the intervening 20 years or so since the INF treaty was concluded in 1987, a number of nations have gone forward with ballistic missile programs within that range band."

Recently, Russian military officials have joined the ranks of those threatening to withdraw from the INF treaty.

And many experts, including Daryl Kimball, head of the Arms Control Association, a private research firm, say there is another reason for the Russian threat.

"One of the catalyzing events leading to these Russian concerns and its threat to withdraw from the INF treaty is the proposal for U.S. missile interceptors in Poland and a sophisticated missile interceptor radar in the Czech Republic," said Kimball. "And it is because of Russia's concerns about the combined capabilities of the U.S. offensive forces and its growing strategic missile defense capabilities that Russia is considering withdrawing from the INF treaty. And the reason why Russia may theoretically do this is to field medium-range missiles in Europe to counter U.S. missile defense capabilities that might be located there."

U.S. officials say the proposed missile defense is needed against potential threats from countries such as Iran. They say it is not targeted against Russia, but officials in Moscow reject that view.

Experts say if Russia withdraws from the INF treaty and decides to resume production of medium-range weapons, this could spark another arms race at a time when relations between Washington and Moscow are not good.