Russia's veto of a Security Council resolution on Syria goes far beyond mere protection for a close ally and arms buyer - it showed Moscow's determination to crush what it sees as a Western crusade to use the United Nations to topple unfriendly regimes.
The same holds true for China, which followed Russia's lead and joined Moscow in its second double veto to strike down a European-Arab draft resolution that would have endorsed an Arab League plan for Syrian
President Bashar al-Assad to transfer power to his deputy to prepare free elections.
Russia's move, analysts and diplomats say, was a diplomatic counteroffensive responding to an unusually active period for the Security Council. Last year the 15-nation panel twice adopted resolutions authorizing "all necessary measures" - diplomatic code for military force - in Libya and Ivory Coast.
Libya and Ivory Coast were also the first time the council invoked the Western-backed notion of the "responsibility to protect" civilians threatened by their own governments.
In both cases UN-authorized military intervention led to the ouster of the countries' leaders. Libya's Muammar Gaddafi was killed at the hands of rebels who overthrew him during a six-month civil war and Ivory Coast's Laurent Gbagbo is now in a holding cell at the International Criminal Court in The Hague.
Russia and China did not stand in the way of UN action in Ivory Coast or Libya, whose civil war was initially the bloodiest of last year's Arab Spring uprisings.
But while Western governments and human rights groups welcomed enforcement of the concept of the "responsibility to protect" civilians, Moscow and Beijing did not hide their disdain for an idea they equate with violating states' sovereignty, which the United Nations was founded to protect.
In the case of Libya, Moscow was infuriated by the decision of France and others to supply weapons to rebels in violation of a UN arms embargo, while NATO appeared to be providing crucial air support for rebel offensives against Gaddafi's forces.
Russia accused the United States and its European allies of tricking fellow Security Council members and using a mandate to protect civilians as a cover for providing support to Libyan rebels and ousting Gaddafi. It was, in short, "regime change."
Russia, which abstained from the March 17, 2011, vote authorizing the use of force in Libya and allowed it to pass, vowed not to let that happen again in Syria, a key weapons-export destination and host to Moscow's only warm-water naval port outside the former Soviet Union.
"I see the Russian veto this week as the latest manifestation of their rejection of the pro-active, norm-enforcing Security Council that has emerged in the past decade," said George Lopez, a professor at Notre Dame University.
"The Libyan case was the final straw for the Russians, hence their October veto of the first Syrian resolution," he said. The second veto on Saturday was more of the same.
RETURN TO COLD WAR DEADLOCK?
The Russian veto goes beyond alliances, revenues from arms sales and Syria's considerable strategic importance for Moscow. It goes to the heart of a deep split between Russia and China, on the one hand, and the West on the other, on whether the United Nations should intervene in internal domestic conflicts.
Russia's and China's support for non-interference should come as no surprise, analysts say. Some Western governments and many human rights groups accuse both Moscow and Beijing of suppressing dissidents at home.
"The Syria vetoes are a dramatic evidence of a longstanding difference between Russia and China and many other countries, but particularly the West," said David Bosco of American University in Washington.
"There are all sorts of political interests involved but there is also a basic difference about whether the international community should be involved in internal conflicts against the will of the government," he said.
Lopez said that Russia had a willing helper in China, which has worked hard to keep the Security Council off the backs of countries that it considers strategic allies, like Myanmar, North Korea and Sudan.
He said China's veto was not a show of support for Assad but "an act of solidarity so that the Russians will support them on North Korean issues at the council."
"And remember - the Chinese have never vetoed on their own, so Russia was - is - really in the lead here," he said.
Frustrated by Russia's determination to block council action on Syria, France and the United States have talked about going outside the United Nations and creating a coalition of countries that would impose tough sanctions on Assad.
Western diplomats on the Security Council said Russia's veto was partly a sign of the coming "re-Putinization" of Russian foreign policy, a sneak preview of the approach Prime Minister Vladimir Putin is expected to take with the West if he returns to the presidency after next month's election, as is widely expected.
With the vote looming, analysts say, it was no surprise Putin took a tough, anti-Western stand on Syria.
So is the Security Council returning to the days of the Cold War when US-Soviet rivalry left the council virtually unable to act? Council diplomats say there is no sign of that.
After the Syria resolution was vetoed on Saturday, French UN Ambassador Gerard Araud told reporters that he did not believe the council was at a general impasse, though it was clearly deadlocked on the issue of Syria.
Nor is this the first time Russia has proven to be difficult for the United States and its allies on the Security Council. In the 1990s, Moscow strongly supported Serbia in the Balkan Wars and acted as Belgrade's protector on the council.
After an ineffectual UN presence failed to stop genocide in the 1992-1995 Bosnian War, the United States and its European allies infuriated Russia by bypassing the deadlocked Security Council and turning to Nato to halt the Serbian onslaught in Kosovo with a bombing campaign against Serbia in 1999.
Russia has also worked hard to dilute UN punitive measures against Iran over its nuclear program during Security Council negotiations on four sanctions resolutions between 2006 and 2010, though it ultimately voted for all of them. But recently Moscow has said there will be no new UN sanctions on Iran.