Saudi Arabia’s King Salman arrives at Vnukovo airport outside Moscow. By SERGEI KARPUKHIN / REUTERS. @Adobe Stock Images.

The United Stated ought to take note, as the leaders of the world’s two top oil producing countries, Russia and Saudi Arabia, meet in Moscow for the first time ever this week. This unprecedented visit by a Saudi king, whose country has been a key U.S. ally since U.S. President Franklin D. Roosevelt first met King Abdulaziz in 1945, illustrates the extent to which Russia has made strategic inroads into the Middle East, particularly as U.S. interest and influence appeared to wane over recent years. It also signals a potentially significant convergence of interests between the two countries, one with important consequences for the U.S.

Russia and Saudi Arabia have historically been at loggerheads, with Riyadh coordinating with Washington throughout the Cold War to promote Islam as a counterweight to Communism in Central and Southeast Asia and the Middle East. The Afghan War in the eighties typified this collaboration, with the CIA and Saudi intelligence teaming up to financially and militarily bleed the Soviet Union, forcing its eventual withdrawal from that country, and ultimately contributing to its eventual collapse in 1990. Until then, Moscow and Riyadh did not even have diplomatic relations.

Since its defeat in Afghanistan, Russia has punched back by propping up U.S. and Saudi rivals in the Middle East, who to date, include Iran, the Assad regime in Damascus, and just about any other Middle Eastern leader or political movement that would challenge U.S. influence.

Moreover, since coming to power, President Vladimir Putin has capitalized on opportunities to drive a wedge between the historic allies, and draw Saudi Arabia closer to Russia. As part of this strategy, Russian propaganda worked tirelessly to inflame U.S. public opinion against Saudi Arabia after the September 11 attacks, insinuating that The Kingdom may have played a role despite its having been at war with Al Qaeda for well over a decade.

Putin’s second opportunity arose with the election of President Barack Obama in 2009 and the divergence of views between the Obama Administration and Saudi leadership over the Iran nuclear deal. In pursuing its signature foreign policy initiative, the Obama administration often derided its Arab Gulf allies, with U.S. officials arguing that the Saudis can complain, but ultimately have no alternative to American protection and the U.S. security architecture in the region. It was a point driven home in shockingly blunt fashion when, in a moment of hubris, President Obama publically dismissed America’s Arab Gulf allies as “free-riders” during a 2016 landmark interview.

Given this backdrop, Saudi Arabia decided to diversify its foreign policy options by taking Putin up on his many solicitations. In June 2015, Saudi Arabia’s Deputy Crown Prince Mohamad bin Salman (MBS) met Putin on the sidelines of the St. Petersburg Economic Forum. Since then, Saudi Arabia has flirted with Moscow, promising to invest billions in the otherwise struggling Russian economy and inking memorandums of understanding with Russian firms in fields such as nuclear power, military equipment, oil and gas and infrastructure development. A joint $10 billion dollar investment fund was set up for that purpose. In return, Riyadh hoped that Putin would use his growing influence to curb the power of Iran and help manage a political transition in Syria away from President Assad.

MBS’s Russia option has borne some fruit, with Moscow providing political cover for the Saudi-led coalition’s war against Iranian-backed militias in Yemen and abstaining from vetoing a United Nations’ resolution sanctioning it. For its part, during the King’s visit, Saudi Arabia is expected to signal its backing for Russian-sponsored ceasefires and “de-escalation zones” in Syria, despite Assad’s continuing hold on power.

More broadly, Russia’s growing stature in the Middle East has afforded Putin the ability to play power broker between regional rivals rather than having to choose. His commanders plan military campaigns together with Iran and Hezbollah in Syria, as he hosts traditional American allies such as the Israeli prime minister and the Turkish president in Moscow. Saudi expectations are tempered by those realities.

Another intriguing aspect of the Saudi-Russian relationship, and one Washington ought to pay special attention to, is not the geopolitics, but rather the two countries’ transformation from traditional competitors to close partners in the global energy market.

Both Saudi Arabia and Russia are rentier economies almost entirely dependent on oil.  The American shale oil revolution and the persistent low oil price environment it contributed to, has incentivized Russia and Saudi Arabia to closely coordinate their petroleum production policies. Reflecting on this new reality while on a visit to Moscow in May of this year, MBS stressed that “there are now no contradictions between Riyadh and Moscow in the oil market.”

This Saudi-Russia coordination on oil pricing is in sharp contrast to previous years, when Saudi-American coordination allowed Washington to use Saudi Arabia as an effective weapon against the Russian economy. Most significantly, by opening up the oil taps and collapsing prices, the Saudis starved the Soviet Union of much needed currency in the mid nineteen eighties, critically damaging the USSR’s financial stability.

American preferred access to Saudi oil, and the two countries’ close cooperation, has been the bedrock of the American-Saudi relationship since its inception, which in turn has been a pillar of U.S. strategy in the Middle East. Putin now has a greater ability to influence, and potentially disrupt, that relationship than ever before.

With Donald Trump’s election to the White House, there has been considerable improvement in Saudi-American relations, with the president promising to get tough on Iran, threatening to annul the nuclear deal, and choosing to make Saudi Arabia the first country he visits as president.

But some sticking points remain; most importantly, for the Saudis, is hesitation at the State Department and Congress to sell Saudi certain advanced weapons systems, most notably, the Theater High Altitude Area Defense (THAAD) anti-missile platform. Saudi Arabia views THAAD as crucial for its defense against Iran’s expanding ballistic missile program. If such weapons’ purchases continue to be delayed, The Kingdom may decide to expand its military procurement relationship with Russia and move toward diversifying its sourcing of major weapons systems.

Ultimately, whether President Trump’s approach to the Middle East will be enough to reverse the thaw in Russian – Saudi relations and reaffirm America’s uncontested standing in the region remains to be seen. Until then, the king of Saudi Arabia and Washington’s other Middle Eastern allies will be on the road to Moscow.