To see why Russia has enthusiastically backed President George W. Bush's call for a global war against terrorism, look at who visited the Kremlin last week.

To see why Russia has enthusiastically backed President George W. Bush's call for a global war against terrorism, look at who visited the Kremlin last week. And to see why that enthusiasm shows signs of flagging so soon, look at who did not. The visitor was Ariel Sharon, the third prime minister of Israel to come to Moscow since 1999. Those visits mark a compelling turnabout since the days when Soviet client states trained anti-Israeli terrorists. Indeed, Mr. Sharon took pains during his Moscow trip to say that the two nations were "united in our concern over the spread of Islamic terrorism." The man who stayed home was Ali Shamkhani, the defense minister of Iran. Protesting Mr. Sharon's visit, Mr. Shamkhani postponed his own trip, which was meant to seal the purchase of hundreds of millions of dollars in Russian arms. This time it was the Russian foreign minister, Igor Ivanov, who took pains to show Russia's other side. After meeting with Mr. Sharon, Mr. Ivanov said that Russia was nurturing its relations with Iran "and shall obviously continue to do so." When it comes to terrorism, Israel and Iran are the two faces of Russia's dry-eyed foreign policy. Russia has been increasingly vocal in its own opposition to terror. It surpassed itself Thursday by offering NATO unsolicited support for a global struggle against terrorist groups. Mr. Ivanov even tacitly endorsed U.S. military retaliation, saying the attacks on the World Trade Center and the Pentagon justified "all possible means" in the fight against terrorism. But within hours, the Russian military pulled back from those positions. The Russian defense minister, Sergei Ivanov, ruled out "even hypothetical assumptions" that Russia and other former Soviet states would lend troops or bases to any NATO military action. Russian officials also warned the United States that any retaliation that caused civilian suffering would only provoke a greater terrorist response. That is precisely the argument the West has used - and Russians have ignored - in Moscow's own war against Islamic extremists in Chechnya. Russia's view of terrorism's threat has moved much closer to that of Western nations. But where the Bush administration now calls for an us-versus-them coalition, Russia's view of the problem is far more shaded. Good relations with Israel are one interest. Moscow's old policy of propping up an Arab bloc dedicated to Israel's extinction died with the Soviet Union. Russia no longer has the money to ship weapons and aid to its old allies. Nor does it have a good reason: today it is Israel, with Western technology, Western entrщe and 1 million Russian immigrants, that has increasingly become the Kremlin's logical Middle East partner. Chechnya is another reason.