Moscow could lose significant influence in the Middle East as nations there react angrily to its bombing of Syrian opposition targets.
A first sign came as Russian gas giant Gazprom said late on October 7 that its massive new pipeline project with Turkey, dubbed "Turkish Stream," would be delayed.
"Given that there is no intergovernmental agreement, the timeframe will be postponed," Gazprom deputy chief executive Aleksandr Medvedev told reporters in Moscow, referring to a deadline next year for building the first of four pipelines.
Moscow has enraged Ankara by launching air strikes against Islamist groups in Syria, including against moderate forces that Ankara supports, and twice violating Turkey's airspace.
Turkey, Saudi Arabia, Qatar, Jordan, and many other states have repeatedly called on Moscow to halt its bombing campaign which began on September 30. The campaign has mostly targeted Syria's secular and moderate Islamist opposition forces, despite the Kremlin's insistence that it is only bombing Islamic State (IS) fighters.
Analysts say the anger is deeply felt in Arab capitals because the Arab states have long insisted that Syrian President Bashar al-Assad step down as the first step to ending Syria's more than four-year civil war.
"It is almost completely unanimous that the Arab governments are against the [Russian] bombing campaign," said Paul du Quenoy, a professor of history at the American University of Beirut who is currently a fellow of the Slavic-Eurasian Research Center at Hokkaido University in Japan. "Most of the Russian targets, including the [secular] Free Syrian Army and most of the Islamist opposition groups, are Sunni Muslims and most of the Arab states have majority Sunni populations."
Saudi Arabia and other Gulf Arab states, along with Turkey, have funneled millions of dollars to Sunni Islamist opposition groups seeking to overthrow Assad's regime, which is largely rooted in Syria's Alawite community, a religious sect that is an offshoot of Shi'a Islam.
Arab public opinion against the Russian campaign also runs high. Dozens of Islamist Saudi Arabian clerics on October 5 called on Arab and Muslim countries to "give all moral, material, political, and military" support for a jihad, or holy war, against Syria's government and its key allies, Russia and officially Shi'ite Iran.
The anger over Moscow's position could translate into diplomatic and economic losses for Russia, which has invested heavily in building its ties with Arab states.
One of Moscow's goals in fostering relations has been to encourage Arab investment in Russia -- something particularly important to Moscow today as the Russian economy reels from low oil prices and Western sanctions over Ukraine.
"Those ties may now very well be frayed by the Russian intervention in Syria," du Quenoy said.
At the same time, Moscow has strong financial interests in the Sunni Arab world, which it regards as a lucrative market for exporting Russian nuclear power technology -- particularly to Egypt, Jordan, and Turkey.
So far, only one Arab capital, Cairo, has spared Moscow from criticism.
"We believe that the [Russian intervention] will have an impact on the fight against terrorism in Syria and help eliminate it," Egyptian Foreign Minister Sameh Shukri said on October 4.
Boris Zilberman, a regional analyst at the Washington-based Foundation for the Defense of Democracies, says Cairo appears to consider cooperating with Russia more important than forcing out Assad.
"That's the dividend from deals that Russia has recently signed [with Egypt] on economic cooperation, arms trade, and a potential agreement on civil nuclear energy cooperation," he says.
Diplomatic and economic relations between Moscow and Cairo have flourished since U.S.-Egyptian ties temporarily cooled over the military overthrow of former president Mohammad Morsi in 2013.
But if anger runs high in most Arab states, it is perhaps still higher in Turkey, another country which has drawn close to Moscow in recent years.
Ankara, which has conducted its own air strikes on IS as part of the U.S.-led coalition bombing the group in Syria and Iraq, has been infuriated by Russian warplanes repeatedly violating its airspace along the Syrian border since October 3.
Turkish President Recep Tayyip Erdogan said on October 6 that his country "cannot endure" the incursions and that "if Russia loses a friend like Turkey, which whom it has cooperated on many issues, it will lose a lot, and it should know that."
On October 7, Prime Minister Ahmet Davutoglu said that Turkey would "not make any concessions in connection to our border security and air space security."
Aaron Stein, a non-resident fellow at the Washington-based Atlantic Council, says Ankara is furious because it sees the Russian incursions as a warning to Turkey not to challenge it in Syria.
"Turkey's historical adversary [Russia] is intentionally breaching Turkish air space, obviously to send a message to Turkey," Stein said. "What's going on, particularly with the air strikes in the northern part of the country is that they are targeting front lines that are manned by rebels heavily supported by Turkey, whose victories in recent months are what appear to have spurred Syria to begin to look even more to its outside patrons, Russia and Iran, for help."
Stein said that the deepening Syrian conflict could make it harder for Ankara and Moscow to develop closer political ties in the future, despite what are cordial relations between Erdogan and Russian President Vladimir Putin. But the analyst predicts that neither side will rush to reduce economic ties.
Turkey is a major market for Russian gas exports by pipeline under the Black Sea and an essential transit state in Russia's plans to one day pipe gas to southern Europe. At the same time, Russian visitors make up a sizable portion of Turkey's tourism industry.
The planned Turkish Stream pipeline project would be a major new area of cooperation. The two sides have agreed in principle on the project but have yet to sign an intergovernmental agreement.
"How long it is postponed for depends on when the agreement gets signed. If the deadline is pushed back by a year, that won't be a tragedy," Gazprom's Medvedev said on October 7. He maintained that political tensions were not a factor.
Turkish Stream, would run from Russia to the edge of the EU at the Turkish-Greek border.
Moscow hopes to one day pipe Russian gas across the Turkish-Greek border and into southern Europe despite Brussels' blocking of Moscow's earlier planned South Stream route. That pipeline was blocked last year over EU charges that Russia's state gas company, Gazprom, engages in monopolistic practices in the European market.
This article has been updated to reflect Gazprom's latest statement on the status of its Turkish pipeline project.