As expected, Turkey will officially not be receiving its order of F-35 Lightning II fifth-generation combat aircraft following its acceptance of delivery of the advanced S-400 air defense system from Russia.

Initial pieces of the first S-400 system ordered by Turkey in October 2017 arrived at Murted Air Base outside the capital city of Ankara on July 12, thereby triggering U.S. sanction requirements under the Countering America’s Adversaries Through Sanctions Act (CAATSA).

Over US Warnings, Turkey Gets Russian-Made S-400 Missile System https://t.co/U061EbFecP — Military.com (@Militarydotcom) July 13, 2019

The financial sanctions related to the CAATSA seek to prevent countries from purchasing Russian weapons systems. Under the sanctions regime, any third party that conducts sizable transactions with the individuals or entities outlined in the CAATSA is liable for punitive sanctions.

Though a waiver may be applied in select circumstances – such as maintenance of legacy Russian systems acquired pre-CAATSA – in Turkey’s case the purchase of the S-400 system increases the risk of compromising U.S. defense items, thus negating this possibility.

Turkey held firm plans for an order of 100 F-35A models, with a total of 30 scheduled for delivery through year-end 2022.

Following months of warnings and tense back-and-forth between Washington and Ankara over Turkey’s insistence on fulfilling its S-400 agreement with Russia, the Pentagon announced earlier on April 1 that it had opted to halt delivery to Turkey of equipment related to the Lockheed Martin F-35.

Turkey’s purchase of the S-400 stoked concerns among U.S. defense officials and those of its allies procuring the F-35. Fears that Turkey’s acquisition and operational use of the Russian system in parallel with the F-35 would provide Russia with a window into the aircraft’s sophisticated technology and vulnerabilities were voiced by Pentagon officials and government policymakers alike. Furthermore, the prospect that Russian contractors sent to support the installation and early operation of S-400 batteries in Turkey would represent an intelligence-gathering threat to U.S. and NATO interests only added fuel to the fire.

By the time the Turkish Defense Ministry made the surprising announcement in February 2017 that the country would be purchasing the S-400 system, Turkey had long been involved in the F-35 program, having become the seventh international partner when it joined the Systems Development and Demonstration (SDD) phase of the F-35 project in July 2002.

The first two fighters produced for Turkey were officially presented by Lockheed Martin on June 21, 2018, in a roll-out ceremony at the company’s Fort Worth, Texas, facility. These two fighters were – until this summer – used to train Turkish pilots and ground crew at Luke Air Force Base in Arizona. Turkish maintenance crews, meanwhile, trained for work on the F-35 at Eglin Air Force Base in Florida.

The fallout from the blocked F-35 order, the loss in workshare to Turkey from F-35 supply chain orders, and the impact of sanctions under CAATSA all threaten to further erode a U.S.-Turkey relationship hindered by the ongoing civil conflict in Syria and the failed coup attempt against Turkey’s strongman president, Recep Tayyip Erdogan, in mid-July of 2016.

Although he sounded sympathetic to Turkey’s position – partially due to the loss of fighter sales for Lockheed Martin, and partially due to interpersonal relations with the Turkish leader and the need for his aid in dealing with regional issues – President Donald Trump reiterated that Turkey would be denied delivery of the F-35. An official statement from the White House was released on July 17.

BREAKING: The U.S. has formally kicked Turkey out of the F-35 Joint Strike Fighter program over Ankara’s buying S-400 missile interceptors from Russia pic.twitter.com/3dxIu6Rif0 — Marcus Weisgerber (@MarcusReports) July 17, 2019

The loss of the advanced stealth fighter will sting Turkey on the airpower capability front, as will the loss of industrial work share associated with the aircraft. According to sources, Turkey’s industrial involvement constitutes up to 6 percent of the value of each plane.

Turkey was slated to serve as the regional hub for final assembly and checkout (FACO) for the F135 engine used on the aircraft, as well as the host of the regional maintenance, repair, overhaul and upgrade facility for the F135. In total, 10 Turkish companies participate in production of parts for the F-35, including the fuselage, landing gear and cockpit displays.

There is also the loss of investment already put into the development of the F-35, which – per a statement by President Erdogan – totals up to $1.5 billion.

But Turkey’s insistence on proceeding with the $2.5 billion purchase of Russia’s S-400 Triumf system prompted U.S. lawmakers and Pentagon officials to advocate for a shutdown on F-35 deliveries and the decoupling of Turkey’s industrial participation in the aircraft’s supply chain.

Going forward, the Trump administration will continue to seek Turkish help in Syria as it prepares for a partial withdrawal of American forces operating in Syria. But such appeals will likely fall on deaf ears in Ankara, where President Erdogan has insisted that it was the U.S. administration that needed to find a middle ground to rectify the “S-400 or F-35, but not both” warning put forth.

While refusing to buckle under U.S. pressure, Erdogan has insisted that Turkey’s choice of the S-400 to provide a long-range air defense interceptor capability was a matter of national sovereignty.

Yet at the same time Ankara has insisted that its choice of the S-400 to meet its immediate requirement for a long-range air defense system was based in part on the technology transfer and joint production presented in the offer – a claim refuted by Russian defense officials. Furthermore, Turkish officials insist that Turkey turned to a Russian air defense option only after the U.S. declined to sell it the Patriot system. But in an attempt to cut the cord on a Turkey-Russia deal last December, the Trump administration offered up the Patriot in exchange for Ankara dropping the S-400 purchase.

The issue is less one of military technology purchased off-the-shelf than of a relationship strained by misunderstandings, a top-down defense procurement decision formulated on a political basis, geopolitical percolations related to the Syria conflict (primarily U.S. support for Kurdish forces battling Islamic State elements), and ensuing fallout from the failed coup d’etat of 2016 that further eroded Turkey’s Kemalist foundations already under siege by Erdogan and his Islamist Justice and Development Party (AKP).

While the S-400 serves as a symbol of Turkey’s drift away from the West under Erdogan, the country remains a NATO member and a valuable geopolitical actor in its own right. Beyond the frozen F-35 sale, how CAATSA sanctions are applied going forward will help determine the level of fallout between Washington and Ankara.