The attack on Saudi Arabian oil facilities last weekend were a disaster for both Riyadh and Washington, with weapons allegedly made in Iran circumventing expensive U.S. missile defence systems

But in Moscow, news of the attack was greeted as yet another chance to mock the United States and its allies - all while extolling the virtues of Russia's own missile defence technology.

"We still remember the fantastic U.S. missiles that failed to hit a target more than a year ago, while now the brilliant U.S. air defence systems could not repel an attack," Russian Foreign Ministry spokeswoman Maria Zakharova told a briefing on Friday. "These are all links in a chain."

Russian President Vladimir Putin, in Ankara for a meeting with Turkish and Iranian leaders on Monday, went further by suggesting that Saudi Arabia would have been saved from Saturday's attack if they had purchased a missile defence system made by Russia.

"The political leadership of Saudi Arabia just needs to make a wise state decision," Putin said on Monday, pointing to the purchase of the S-300 missile system by Iran and the S-400 missile system by Turkey.

The rivalry between the United States and Russia over arms sales has existed ever since the Cold War; between 2014 and 2018, they were the two largest exporters of arms in the world, according to the Stockholm International Peace Research Institute.

But over the past few years, that rivalry has grown especially bitter as geopolitical conflict and new technology brought U.S. and Russian arms into close contact. In the Middle East, where tension and war have led to a surge in arms sales, Washington and Moscow often compete for the same clients.

Though the United States generally claims to offer superiority, some weapons systems produced by Russia are challenging that. Chief among them is the S-400 missile defence system, a widely-touted - though ultimately untested - rival to the U.S.-made Patriot missile system.

The attack on the oil facilities in the Saudi districts of Khurais and Abqaiq on Saturday morning appeared to involve cruise missiles and drones that were able to avoid detection by and activation of Saudi Arabia's missile defence system.

Notably, that system includes Patriot batteries and it is generally designed to combat ballistic missiles and airplanes that can be spotted from further away.

As cruise missiles and drones can fly closer to the ground, the curvature of the earth makes them harder for radar to spot unless the radar is elevated.

Russia's systems are capable of using mobile radar masts to combat this problem. The S-400 is also designed to operate in any direction, whereas Patriot systems are limited to whatever direction they are set up in: some analysts have suggested that many of the Patriot batteries deployed near the oil facilities targeted on Saturday may not have been looking in the right direction to deter the attack.

"This Saudi attack shows the absolute imperative of 360 degree capability," said Tom Karako, the director of the Missile Defence Project at the Center for Strategic and International Studies.

While Russia's S-400 system may have impressive specifications on paper, many analysts are cautious in their assessment of it. It has not been fully tested in real life, whereas the Patriot system successfully intercepted missiles during both the Gulf War and the U.S.-led invasion of Iraq.

Some research has also pointed to potential weak spots in the S-400′s system. Russia's military industrial complex is known for its secrecy about potential military failures: in recent months, the country has seen a mysterious missile explosion and a deadly accident on a nuclear submarine, while last year a covert Russian mercenary group in Syria suffered a humiliating defeat by U.S. forces.

But Moscow disputes the efficacy of U.S. weapons as well. As Zakharova said Friday, Russia dismissed the impact of missile strikes by the United States, along with Britain and France, in April 2018 on targets in Syria after the use of chemical weapons by forces loyal to Syrian President Bashar al-Assad.

At the time, Russia claimed that Syrian air defences had shot down 71 of 103 missiles fired; the Pentagon denied this figure and Moscow provided no evidence. Russia has supplied antimissile systems to Syria, but it said that S-400s deployed to protect a Russian base in Syria only monitored the attack.

For all the rivalry between American and Russian weapons systems, the battle has mostly played out on the political level so far. Moscow has courted a number of U.S. allies to purchase Russia's missile defence systems, which cost considerably less than their American counterparts. India and Qatar have publicly mulled buying the S-400.

NATO ally Turkey announced it intended to buy the system this summer, prompting the United States to suspend Turkish involvement with the American F-35 program. Kathryn Wheelbarger, U.S. acting assistant secretary of defence, had said in May that the "S-400 is a Russian system designed to shoot down an aircraft like the F-35," an advanced U.S. stealth fighter.

In theory, the range of a surface-to-air missiles carried by an F-35 should allow it to destroy an S-400 before it is detected by its radar, but that idea has not been tested in practice. Both Washington and Moscow likely hope that it will never will be: For both countries, a little ambiguity can be lucrative.