Editor's note: Paul Antonopoulos is managing editor of Fort Russ News, director of the newly-established Center for Research on Multipolarity and a research fellow at the Center for Syncretic Studies. The article reflects the author's opinion, and not necessarily the views of CGTN.

Russian President Vladimir Putin aims to strengthen and deepen ties with Saudi Arabia on his Thursday visit to the Middle Eastern kingdom. He will take a particular focus on energy, oil and, most importantly, defense. His visit comes at an especially critical time as Saudi Arabia is struggling to achieve its objectives in Yemen while U.S. influence in the region is giving way to that of Russia.

U.S.-Saudi relations have traditionally been strong. Since the rise of Prince Mohammed bin Salman, his reform to the domestic economy has increased demand for U.S. arms, and coupled with Saudi Arabia's intense rivalry with Iran while improving relations with Israel, all these have ensured the new leader of the country keep close relations with the U.S.

However, cracks between the two traditional strong allies are beginning to emerge, starting with their differences over Syria. The U.S. accused Saudi Arabia of murdering journalist Jamal Khashoggi, while Saudi Arabia feels upset that the expensive U.S. weapons fail to defend Saudi airspace.

Two major Saudi oil refineries were attacked by the Yemeni Houthi-led Ansarullah movement in September, resulting in rising oil prices and supply concerns globally as half of Riyadh's oil production was affected by the attacks. This powerful attack by the Houthi forces was achievable just because the Saudi air defenses were easily compromised by drones. This, of course, brought into question the costly U.S.-made Patriot Missile Defense System. The U.S. has always been the main arms supplier to Saudi Arabia, and their relationship has intensified further since President Trump took office, with 110 billion U.S. dollars' worth of U.S. arms sold to Saudi Arabia just months after his inauguration in January 2017.

Since Saudi Arabia has six battalions of U.S.-made Patriot Missile Defense Systems, each worth 1 billion U.S. dollars, the country's air defenses should have easily downed the Houthi drones that attacked the Saudi oil facilities. This failure prompted Putin shortly after the attack to say that Saudi Arabia should buy the Russian-made S-300 or S-400 missile defense system, as Iran and Turkey have already done, by claiming that "we are willing to provide appropriate assistance to Saudi Arabia.”Therefore, there can be little doubt that a huge part of Putin's trip to Saudi Arabia will be focusing on the sale of the S-400.

Putin has used S-400 diplomacy before to strengthen relations with other states and move them away from the U.S. orbit. The most famous case is Turkey. Despite being a NATO member and receiving threat of sanctions from the U.S., Turkey insisted on purchasing the S-400, as it knows that it is the most powerful anti-air defense missile system in the world today.

Therefore, the failure of the Patriot system to defend Saudi Arabia has provided a perfect opportunity for Putin to use the S-400 diplomacy with a state that has traditionally been the strongest Arab ally of the U.S. in the Middle East. With Saudi security easily undermined by Houthi drones, it is likely that the Saudi leadership will seek a stronger relation with Russia who can provide alternative weaponry from the U.S.

The key question then is, will Saudi Arabia become a Russian ally after Putin's visit? Although Putin will surely emphasize the ineffectiveness of the Patriot system and push for the sale of the S-400, the Saudis will seriously consider their deep pockets and their continued efforts to ensure security, therefore, deals relating to economics and energy will surely also be strengthened after Thursday. However, it is unlikely that Saudi Arabia will become a staunch Russian ally, and it will probably opt to adopt a balancing policy to not antagonize either the U.S. or Russia.

Given Russia's assistance to Turkey's defiance of NATO, its defense of the Syrian government against U.S.-backed armed groups, and new opportunities to be potentially exploited in Saudi Arabia (purchasing the S-400 system), it would suggest that Russia is changing the Middle East order and system that has traditionally been dominated by the U.S. with the growing Russian influence across the region.

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