Russia, unlike energy-desperate China, is practically drowning in oil and natural gas, but has an abiding interest in not seeing energy-rich neighboring Iran fall under the sway of the U.S. and, as a major supplier of nuclear equipment and technology, also has a special interest in lending a profitable hand to Iran's energy establishment. The Russians are completing the construction of a civilian nuclear reactor at Bushehr in southwest Iran, a $1 billion project, and are eager to sell more reactors and other nuclear energy systems to the Iranians. This, of course, is a source of considerable frustration to Washington, which seeks to isolate Tehran and prevent it from receiving any nuclear technology. (Although an entirely civilian project, Bushehr would no doubt be on the target list for any American air attack intended to cripple Iran's nuclear capacity.) Nevertheless, the head of the Russian nuclear energy agency, Sergei Kiriyenko, announced in February, "We don't see any political obstacles to completing Bushehr" and bringing it on line "in the swiftest possible period."

Given what is at stake, it is easy to see why the United States, Russia, and China all have such an abiding interest in the outcome of the Iranian crisis. For Washington, the replacement of the clerical government in Tehran with a U.S.-friendly regime would represent a colossal, threefold accomplishment: It would eliminate a major threat to America's continued dominance of the Persian Gulf, open up the world's number two oil-and-gas supplier to American energy firms, and greatly diminish Chinese and Russian influence in the greater Gulf region.

From a geopolitical perspective, there could be no greater win on the global chessboard today. Even if Washington failed to achieve regime change but, using its military might, crippled Iran's nuclear establishment without sustaining major damage itself in Iraq or elsewhere, this would still be a significant geopolitical win, exposing the inability of either Russia or China to counter American moves of this sort. (This would only work, of course, if the Bush administration was able to contain the inevitable fallout from such action, whether increased ethnic strife in Iraq or a sharp spike in oil prices.)

Not surprisingly, Moscow and Beijing are doing everything in their power to prevent any American geopolitical triumph in Iran or Central Asia from occurring, though without provoking an outright breach in relations with Washington -- and so endangering complex economic ties with the United States.

As this grand geopolitical "Great Game" unfolds, with the potential economic well-being of the planet at stake, all sides are trying to line up allies wherever possible, using whatever diplomatic levers are available. Since the invasion of Iraq in 2003, the U.S. position in both the Persian Gulf and Central Asia has noticeably deteriorated. At present, the Bush administration's greatest weakness remains the schism in U.S.-European relations created by the unilateral U.S. invasion itself. Because the Europeans felt betrayed by that action, they have largely refrained from helping out either in the counterinsurgency effort in Iraq or in funding the reconstruction of the country. This has imposed a ghastly and mounting cost on the United States. Fearing a repetition of this fiasco in Iran, the White House has clearly decided to let the diplomatic process play out on the Iranian crisis in a way they refused to do when it came to Saddam's Iraq. So, within limits, they are letting the Europeans set the diplomatic game plan for "resolving" the nuclear dispute.

This, in turn, has given Moscow and Beijing their one obvious option for averting what could be a geopolitical disaster for them in Iran: the potential use of a Security Council veto to block the imposition of U.S.-threatened sanctions on Iran under Chapter 7 of the UN Charter, which could legitimize not only such sanctions but also the use of force against any state deemed to pose a threat to international peace. The Europeans want to prevent such a vote from occurring -- knowing that any "failure" at the UN might only strengthen the arguments of the hawks in Washington who want to move unilaterally and by force against Iran. As a result, they are listening to the Russians and Chinese who insist on relying on diplomacy -- and nothing else -- to resolve the crisis, however long that takes.

"Russia believes that the sole solution for this problem will be based on the work of the IAEA [International Atomic Energy Agency],"said the Russian foreign minister, Sergey V. Lavrov, in March. Very similar statements have been issued by Chinese officials, who have expressly ruled out force as an acceptable solution to the crisis. In February, for instance, the Chinese Ambassador to the IAEA, Wu Hailongon, called on "all relevant parties to exercise restraint and patience" and "refrain from any action that might further complicate or deteriorate the situation."