Saudi Arabian King Salman bin Abdulaziz's groundbreaking visit to Russia this week saw billions of dollars signed in investment deals in energy and defense that will deepen ties between Moscow and Riyadh, despite their confrontational past.
But analysts say self-interests and Middle East alliances will hamper the forming of a deeper partnership.
During this first trip to Russia by a Saudi king, the two sides agreed on billions of dollars in projects involving space exploration, nuclear energy and oil, including a $1 billion fund on energy cooperation and a $1 billion fund on high-tech investment.
Even the king's 1,500-strong entourage, which Bloomberg said booked two luxury hotels just off Moscow's Red Square for the four-day visit, gave a small boost to Russia's economy.
Seeking new partners
Despite the U.S. being its major arms supplier, Riyadh also signed deals on manufacture of Kalashnikov arms and a surprise purchase of Russian weapons systems, such as the advanced S-400 missile defense system.
While the administration of U.S. President Donald Trump has taken a harder line on Iran, uncertainty in America's Middle East policy has encouraged Riyadh to forge new partnerships, analysts say.
"Saudi Arabia is looking for allies in its non-easy relations with Iran, while Russia is confronting sanctions and is interested in serious partners," said Mikhail Subbotin of the Russian Academy of Sciences' Institute of the World Economy and International Relations. "The sanctions made it look for new allies and activate relations with long-standing partners."
Sunni-led Riyadh wants Moscow to help rein in Shiite-led Tehran's influence in the Middle East.
Meeting with Russian President Vladimir Putin on Thursday at the Kremlin, King Salman said security and stability in the Persian Gulf and the Middle East is the most eagerly sought after and essential prerequisite for achieving security and stability in the world.
"This requires that Iran abandon attempts to interfere in the domestic affairs of the states in the region and stop the activity that destabilizes the region," he said.
Questionable influence over Iran
But it is not clear that Russia has much influence over Iran or any desire to pressure Tehran.
Russia also deals with Iran on oil and last year began delivering less-advanced S-300 missiles to Tehran.
In Syria, Riyadh is on the opposing side to Moscow and Tehran in regards to Damascus. Russia is allied with Iran against militants fighting to overthrow Syrian President Bashar al-Assad, including some backed by the U.S. and Saudi Arabia.
"In Syria, these two countries have much in common in their fighting against terrorism, but Saudi Arabia is part of a large coalition while Russia supports Assad," the Russian Academy's Subbotin said.
Observers noted the Saudi king in his public remarks on Syria to Putin did not mention seeking Assad's removal from power, an indication that Riyadh's long-standing position of regime change is no longer its main objective.
"As concerns the Syrian crisis, we are committed to pushing for its resolution in line with the Geneva I decisions and U.N. Security Council Resolution 2254, to finding a political solution that would guarantee security, stability, and Syria's unity and territorial integrity," King Salman said.
Russia's military intervention in Syria succeeded in turning the tide of defeat away from Assad, analysts say, and demonstrated Moscow's return to the world stage as a major player in the Middle East.
The plunging price of oil has also led to closer relations between the world's two biggest oil producers. Mutual concerns of maintaining a stable price on crude, the biggest contributor to both their economies, produced an agreement to limit output.
"We are striving to continue the positive cooperation between our states to achieve stability in the global oil market, which will facilitate global economic growth," King Salman said Thursday at the Kremlin.
But Russia does not always hold such agreements, as it is guided by its own interests, said Mikhail Krutikhin, an analyst and partner in the Rusenergy consulting company.
"There is a certain formalized agreement dealing with a reduction of oil volume between OPEC [Organization of the Petroleum Exporting Countries] countries and Russia, as well as some other countries," Krutikhin said. "Here is a following issue: Russia does not implement its obligations. It increased oil exports, thus not helping to keep the prices at a high level but obstructing that."
Cheating on agreed oil output caps has dogged OPEC since its founding, because those who break any such deals, whether members or not, stand to benefit more than those who stand by it.
"Russia is guided by its own interests," Subbotin said. "Sometimes it de facto joined the coalition with OPEC and supported a policy aimed at reducing oil production; sometimes OPEC was reducing the extraction but Russia was increasing it.
"At the current stage, the interests of Russia and those of Saudi Arabia have coincided," he added.
VOA's Danila Galperovich contributed to this report.