The proliferation of advanced Russian made anti aircraft weapons systems, and particularly the S-400 Triumf long range surface to air missile platform, to a number of countries across the world has been perceived as a major threat by the Western Bloc, which as stringently opposed and attempted to disrupt sales to several states. The United States has taken a leading role in applying pressure on potential clients not to acquire the system, though interest in the Russian air defence platform as well as its predecessor the S-300 has increased dramatically since their prolific deployment to Syria in 2015. With Western powers relying heavily on aerial warfare to project power globally, acquisition of advanced air defence capability by neutral or Russian aligned states, even by Western allies, potentially threatens to restrict the Western Bloc's ability to freely deploy force to theatres across the world.
A number of states including Turkey, Iraq and India have been threatened with serious consequences including Western economic sanctions should they acquire the S-400, despite all of these being close Western defence partners and Turkey itself being a NATO member. One exception appears to have been the Western Bloc's oldest and most strategically critical economic and defence partner in the Middle East, the Kingdom of Saudi Arabia, which itself entered negotiations with Russia in October 2017 to acquire the S-400 system. It did so without open threats of economic sanctions or restrictions on weapons to the country by the West.
Saudi Ambassador to Russia Rayed Krimly stated in an interview with Russian state media in June 2018 regarding the S-400 acquisition: "We are still continuing technical details of the agreement. We signed the contract during the King's visit, what is now happening is the implementation requires technical details of technology transfers, other technical details between experts of both sides. It is no secret that Russia's Rostec already opened an office in Saudi Arabia. We moved ahead with 3 other agreements because they were more simple in nature. But we expect movement in this agreement. Experts need to finish their discussions, we can't put a date for the end of discussions, but it is proceeding in a very positive manner. Frankly speaking, we have so many delegations already meeting on this issue. Whether the meeting is in Saudi Arabia or they are meeting in Russia sometimes - it is on a continuous basis."
While Saudi Arabia's acquisition of the S-400 and Riyadh's growing defence partnership with Moscow undermines the Western Bloc's efforts to isolate Russia internationally and undermine its defence related exports, the Arab Kingdom's strategic importance and its financial clout and regional influence make the risk of Isolating Saudi Arabia far too great. With Saudi Arabia being by far the largest importer of arms in the world, and one of the largest investors in both Western Europe and the United States, the risk of souring relations with the country appear too great to risk. The recent failures of U.S. made air defence platforms such as the Patriot to protect Saudi airspace, and the S-400's primary purpose of strengthening Riyadh's defences against Iran which Western suppliers have been unable to achieve, makes the idea of Saudi operated S-400 batteries protecting Riyadh more palatable.
Saudi arms acquisitions from Russia appear limited in their scope, and the S-400 system, though expensive, represents only a very small fraction of Riyadh's expenditures on foreign arms - the vast majority otherwise going to Western producers. Indeed, alongside the S-400 the Arab state has also placed orders for U.S. made Patriot missile batteries and even the THAAD (Terminal High Altitude Air Defence) system, despite the latter's apparently limited usefulness given its purpose of intercepting intercontinental ballistic missiles and Riyadh's close proximity to its adversaries. These acquisitions alone cost several times as much as the S-400 system. Saudi influence in the Middle East and its vital importance to mainlining the Western dominated regional order, combined with its vast expenditures which are critical to propping up Western producers, particularly those in Europe which often struggle to export their costly wares, means Riyadh's acquisition of a Russian weapons system for its defence is likely to be looked over. How other lower tier Western regional partners such as Iraq and Qatar will look to this remains to be seen.