The Russian foreign ministry has issued a warning to President Obama and other western countries that might join the US in attacking ISIS in Syria: Without a UN Security Council resolution authorizing the strikes, the Russian government would consider any attack on Syrian soil "aggression."

President Obama has no plans to seek authorization for his actions from the security council where it would probably be vetoed by Russia, or China, or both. This would set up another potential confrontation with Moscow, on top of the tension over Ukraine.

Reuters:

"The U.S. president has spoken directly about the possibility of strikes by the U.S. armed forces against ISIL positions in Syria without the consent of the legitimate government," Foreign Ministry spokesman Alexander Lukashevich said.

"This step, in the absence of a U.N. Security Council decision, would be an act of aggression, a gross violation of international law."

Barack Obama said on Wednesday he had authorized U.S. air strikes for the first time in Syria and more attacks in Iraq, in an escalation of the campaign against the Islamic State militant group, which has taken control of large areas of both countries.

Western states have ruled out working with Syrian President Bashar al-Assad, saying he has indirectly helped Islamic State grow in order to weaken other opposition groups.

Obama, who is due to host a leaders' security conference at the U.N. General Assembly in two weeks' time, made no mention of seeking an international mandate for action in Syria.

Russia, a veto-wielding permanent member of the Security Council, has given Assad crucial backing in Syria's civil war, which has killed more than 200,000 people.

It has provided arms and blocked Western and Arab-backed efforts to adopt Security Council resolutions condemning him or threatening him with sanctions.

It has repeatedly argued that it does not believe the Syrian opposition can fill the void that would be left by Assad's departure, warning the country would fall into the hands of Islamic militants.

France, a key ally for the United States in the planned coalition, said on Wednesday it was ready to take part in air strikes in Iraq, but said its involvement in any military action in Syria would need to have international law behind it.

Foreign Minister Laurent Fabius said the Iraqi government has asked for help internationally, but in Syria the legal basis would have to be established first.

French officials have said that would come either through a Security Council resolution or under Article 51 of the U.N. charter, allowing for protection of threatened populations.

Great Britain has already politely declined to participate in any military action in Syria, so, as expected, the US will be going it pretty much alone. With NATO on the sidelines, the Arab countries cheering us on from afar, and the "international community" willing to fight to the death of the last American, the Syria operation will reveal the nauseating hypocrisy of the rest of the world when it comes to America's super power status. Everybody hates us, villifies us, and criticizes us - until they beg us to save them from the barbarians. 

A UN resolutiion would be a PR move anyway, given that body's total incapacity to act in a way that matters. But as long as we don't directly engage Syrian troops, it is unlikely that Russia will complain very much if we destroy the ability of Islamic State to make war in Syria.