How long will UN unanimity last?

It is rare that all 15 members of the United Nations Security Council approve a tough resolution on a Middle Eastern question.

So Monday's unanimous vote to demand Syria's full cooperation with the international investigation of former Lebanese premier Rafik Hariri's assassination shows just how isolated Damascus has become. But the vote also disguises considerable differences of approach among key players.

Russia and China, along with the only Arab nation on the Security Council, Algeria, refused to go along with Washington's desire to threaten economic sanctions against Syria should Bashar Assad's regime not cooperate.

To win unanimous support, France, Britain, and the US, who jointly sponsored the resolution, had to drop all references to sanctions other than a warning that the council "could consider further action" if Syria does not hand over for interrogation senior officials suspected of involvement in Mr. Hariri's murder.

Russia - a traditional ally of Syria's - "is very reluctant to endorse any sanctions when it is unclear where they might lead in the future," says Oxana Antoninka, a Russia expert at the International Institute for Strategic Studies, a think tank in London. "Moscow wants to prevent the Security Council from becoming a weapon to punish regimes that could lead to unforeseen action such as military action."

Algerian ambassador to the UN Abdallah Baali spoke for several other Council members when he argued that "it is premature and unjustified to talk about sanctions when the investigation is still going on." UN investigator Detlev Mehlis has been given until Dec. 15 to complete his inquiries into Hariri's death.

And while France and the US have been working together on Lebanon since they jointly sponsored a UN resolution last year calling on Syrian troops to withdraw from Lebanon, Paris, and Washington appear to have divergent purposes now.

The United States is seeking a radical change in the nature of the Syrian regime. US Secretary of State Condoleezza Rice said Monday the resolution showed that "Syria has isolated itself from the international community through its false statements, its support for terrorism, its interference in the affairs of its neighbors and its destabilizing behavior in the Middle East." Dr. Rice called on Damascus to "make a strategic decision to fundamentally change its behavior."

French Foreign Minister Philippe Douste-Blazy (whose boss, President Jacques Chirac, was a personal friend of Hariri) gave the resolution a much narrower purpose. Its aim, he told reporters, was to find "the truth, the whole truth about Rafik Hariri's assassination in order that those responsible for it answer for their crime."