In the old westerns, it was not uncommon to see a final showdown in which the white hats confront the black hats with an accusation of perfidy: "So it's you that's been sellin' rifles to those Injuns." Something like these recriminations is taking place on an international scale now, although there is more than one seller and the consequences are more ominous.

In late October, the Russian newspaper Kommersant reported that China's Chengdu Aircraft Industry Group will sell 24 of its new-generation Jian-10 (J-10) fighter aircraft to Iran in a contract valued at $1 billion. The Moscow-based daily received the information from a source inside HESA--a division of the Iran Aircraft Manufacturing consortium. This would be the first purchase of a new-generation combat system by the Iranian air force since the early 1990s. (China's state-run Xinhua news agency denounced the story as "false and irresponsible" and denied that there have been any negotiations, but did not outright deny the sale.)

Last week, the Paris-based defense and strategy publication TTU reported that China is planning to supply the J-10 to Syria as well. The Chengdu fighter would replace an aging arsenal of Russian aircraft largely acquired by Damascus during the Soviet era. Intelligence on the growing cooperation between Syria and Iran indicates that Tehran will finance this Syrian procurement. Having the two allied nations operate the same front-line fighter aircraft will create economies of scale, for instance by allowing maintenance and servicing facilities to be shared.

Russia's connection to the J-10 and the reason for the report originating from Kommersant is that the J-10s are powered by the AL-31FN jet engine built by the Salyut Production Association in Moscow, generally considered to be the most advanced military engine manufacturer in Russia. Chinese industry has struggled but failed to develop a reliable, high-performance jet engine. Both of China's new-generation fighters--the J-10 and the FC-1/JF-17--are powered with Russian engines.

Iran has until now been reluctant to purchase much in the way of new aircraft, having been content to maintain their older-model U.S.-built aircraft that they acquired during the time of the shah. Iran also has its own indigenous jet program, the Saeqeh (Lightning). But this plane is a copy of the old Northrop F-5, and is at least two generations removed from state-of-the-art military technology.

The Chinese J-10s are to be delivered between 2008 and 2010 and appear to be meant to replace the aging J-7 fighters that were acquired from China more than two decades ago in the Khomeini era. The J-7, interestingly, is flown not by the regular Iranian air force, but by the air arm of the Iranian Revolutionary Guard Corps. The J-10's mission, according to a Russian military analyst who spoke to the Novosti news agency in Moscow, will be to defend Iran's Bushehr nuclear reactor site, which is being completed with Russian assistance.

Chinese-Iranian cooperation is not news. Iran has been a buyer of Chinese weapons since the early days of the Islamic Republic, and Chinese-designed weapons have been produced under license in Iranian factories. Last July during the military conflict with Hezbollah, an Israeli naval vessel was heavily damaged by an Iranian-produced model of the Chinese C802 antiship missile.