The New York Times reports that Neo-Soviet Russia is now the world's leading arms merchant, surpassing the U.S. in dealing instruments of destruction. Nearly one out of every four dollars spent on weapons by developing nations goes to Russia.

Russia surpassed the United States in 2005 as the leader in weapons deals with the developing world, and its new agreements included selling $700 million in surface-to-air missiles to Iran and eight new aerial refueling tankers to China, according to a new Congressional study. Those weapons deals were part of the highly competitive global arms bazaar in the developing world that grew to $30.2 billion in 2005, up from $26.4 billion in 2004. It is a market that the United States has regularly dominated.

Russia’s agreements with Iran are not the biggest part of its total sales — India and China are its principal buyers. But the sales to improve Iran’s air-defense system are particularly troubling to the United States because they would complicate the task of Pentagon planners should the president order airstrikes on Iran’s nuclear weapons facilities.

The Bush administration has vowed a diplomatic solution in dealing with Iran. But as United Nations diplomats argue over potential sanctions against Iran for its nuclear ambitions, Russian officials have expressed reluctance to vote for the most stringent economic sanctions, partly owing to Moscow’s extensive trade relations with Tehran.

Russia’s weapons sales to China also worry Pentagon planners. Although China has joined the United States in partnership to press for a resumption of six-party talks to end North Korea’s nuclear weapons program after its recent test, Taiwan remains a potential flash point between Beijing and Washington.

Thus, China’s ability to refuel its attack planes and bombers to enable them to fly farther from Chinese soil could require the United States Navy to operate even farther out to sea should the United States military be called to deal with a crisis in the Taiwan Strait. That would have an impact on the range and number of air missions of United States Navy aircraft launched from carriers.

Details of the specific weapons deals in the global arms trade last year are included in an annual study by the Congressional Research Service that is considered the most thorough compilation of statistics available in an unclassified form. The report was delivered to members of Congress on Friday.

Among other arms transfers described in the study was a statistic that a single, unnamed nation — but one identified separately by Pentagon and other administration officials to be North Korea — shipped about 40 ballistic missiles to other nations in the four-year period ending in 2005, the only nation to have done so. Transfers of these weapons are prohibited under international agreements to control the trade of ballistic missiles.

United Nations sanctions passed earlier this month after the North Korean nuclear test include a new and specific ban on trade or transport of ballistic missiles and missile parts to or from North Korea.

The report, entitled “Conventional Arms Transfers to Developing Nations,” found that Russia’s arms agreements with the developing world totaled $7 billion in 2005, an increase from its $5.4 billion in sales in 2004. That figure surpassed the United States’ annual sales agreements to the developing world for the first time since the collapse of the Soviet Union. France ranked second in arms transfer agreements to developing nations, with $6.3 billion, and the United States was third, with $6.2 billion.

The leading buyer in the developing world in 2005 was India, with $5.4 billion in weapons purchases, followed by Saudi Arabia with $3.4 billion and China with $2.8 billion.

The total value of all arms sales deals worldwide, when counting both developing and developed nations, in 2005 was $44.2 billion.

The Russian sales in 2005 included 29 of the SA-15 Gauntlet surface-to-air missile systems for Iran; Russia also signed deals to upgrade Iran’s Su-24 bombers and MIG-29 fighter aircraft, as well as its T-72 battle tanks. “For a period of time, in the mid-1990s, the Russian government agreed not to make new advanced weapons sales to the Iran government,” wrote Richard F. Grimmett, author of the study by the Congressional Research Service, a division of the Library of Congress. “That agreement has since been rescinded by Russia. As the U.S. focuses increasing attention on Iran’s efforts to enhance its nuclear as well as conventional military capabilities, major arms transfers to Iran continue to be a matter of concern.”

Russia also agreed in 2005 to sell China eight of the IL-78M aerial refueling tanker aircraft, according to the study.

In 2005, the United States led in total arms transfer agreements, when deals to both developed and developing nations are combined. The total was $12.8 billion, down from $13.2 billion in 2004.

The report charted no blockbuster military sales deals by the United States in 2005, and the total in many ways was reached by sales of spare parts for weapons purchased under previous contracts.

France ranked second in total sales, with $7.9 billion, up from $2.2 billion in 2004. Russia was third when sales to developing and developed nations were combined, with $7.4 billion, up from $5.6 billion in 2004.

The study uses figures in 2005 dollars, with amounts for previous years adjusted to account for inflation.