In its ties with Turkey, the United States finds itself in a classic Catch-22. Turkish foreign policy often runs afoul of U.S. interests. However, Ankara is also a member of NATO, America’s most important alliance. Thus, any move to punish Ankara for threatening Western interests would weaken the Turkish military and undermine the longstanding U.S. policy goal of increasing the capabilities of its allies, especially those facing Russia along NATO’s eastern flank.
Turkey’s purchase of Russia’s S-400 air and missile defense system is a perfect example of Washington’s dilemma. In December 2017, Ankara finalized an agreement with the Russian Federation for the purchase of the S-400. In response, the United States removed Turkey from participation in the F-35 fighter aircraft program, because the S-400 can collect valuable electronic intelligence on the West’s newest jet. This outcome upended decades of Turkish planning for the future of its air force. While Ankara has plans to develop an indigenous fighter, any such program will likely be extremely expensive, face serious delays, and may not deliver enough fighter aircraft to replace its current inventory of F-16s. The problem now is to protect the F-35 from Russian exploitation — even after Turkey has taken ownership of the S-400 — while developing a mechanism to ensure Turkey can purchase new fighter aircraft.
America’s experience with another troublesome ally — Pakistan — might have valuable lessons for U.S. defense officials in dealing with Turkey. The United States has sold and upgraded F-16s to Pakistan since the 1980s despite Islamabad’s support for the Taliban and Haqqani Network, growing nuclear arsenal, and use of terrorist groups to attack India. In order to buy F-16s after 9/11, Pakistan agreed to a program that allows U.S. technical security teams to monitor the end-use of the aircraft. A similar program could serve as a model to keep tabs on any future Turkish use of the F-35 and ensure a highly circumscribed S-400 deployment. The application of this strategy to Turkey faces a number of challenges, particularly given the state of Turkey’s deteriorating relationship with the United States and other Western countries. However, it may be the only realistic approach to protect the F-35 program and America’s interest in a capable Turkish Air Force.
The Threat of Sanctions and the American Counter-Offer
Turkey’s purchase of the S-400 ran afoul of the Countering America’s Adversaries Through Sanctions Act, a bipartisan sanctions package passed in August 2017 to limit President Donald Trump’s ability to unilaterally lift sanctions imposed on Russia for its interference in the 2016 election. The legislation requires the president to impose secondary sanctions on countries or individuals that engage in a “significant transaction” with any entity linked to Russia’s Ministry of Defense.
Buying a Russian-made air defense system most certainly met the definition of “significant transaction,” but Trump has ignored the law and resisted imposing sanctions on Ankara. In response, Congress has also sought to protect the F-35 from flying regularly in the same airspace as the S-400 to prevent Russia from gathering intelligence on America’s premier fighter aircraft. Turkey was a member of the F-35 consortium since 2001, paying an initial $175 million to help develop the jet. It invested hundreds of millions more throughout the F-35’s development for upgrades to Turkish bases in preparation to take ownership of at least 100 jets. A slew of Turkish companies also manufacture parts of the F-35 (including some where Turkish firms are the sole supplier) and Ankara was slated to be a hub for engine maintenance for F-35s sold to European countries (i.e., Belgium, Denmark, Italy, Poland, the Netherlands, Norway, and the United Kingdom).
During Ankara’s negotiations with Moscow on the S-400 purchase, the United States warned Turkey that finalizing the agreement could lead to Turkey’s removal from the F-35 program. Ankara ignored the warning, perhaps reasoning that it could create a mechanism to assuage U.S. concerns about Russia collecting electronic information about the aircraft so that it could operate both systems. This proved to be a bad bet. In the Fiscal Year 2019 National Defense Authorization Act, the United States commissioned a study to identify alternative suppliers to replace Turkish firms in the F-35 program. It then removed Turkey from the program altogether, blocked the transfer of the jet, and appropriated money for the U.S. Air Force to purchase the jets made for Turkey and upgrade them to meet American specifications.
The American approach did not rely solely on sticks. Between the FY2019 National Defense Authorization Act, when the study was first commissioned, and FY2020, when Ankara was officially removed from the program, the United States sought to offer Turkey an alternative air and missile defense system. The American proposal to Turkey for the export of two systems — the National Advanced Surface to Air Missile System and the Patriot missile system — came amidst broader bilateral acrimony. Turkey detained American pastor Andrew Brunson and the tensions over his detainment reached as high as the White House. Still, despite this, the Trump administration convinced a Turkey-skeptical Congress to authorize the export of both systems. By this point, however, the U.S. offer was too late. Ankara and Moscow already reached an agreement on a Russian loan for the purchase of the S-400, and plans were underway to begin the training of Turkish crews in Russia to operate the system.
The Turkish government began to receive its S-400 from Russia in July 2019 and accepted final delivery of the first of two regiments in January 2020. During this delivery, Ankara went as far as to test the S-400 radar against the F-16 in a showy display of defiance, undoubtedly intended to signal to the United States that Turkey was committed to using the S-400 regardless of a potential U.S. backlash. However, Turkey’s calculations changed after a severe economic downturn and the onslaught of the COVID-19 pandemic. In the face of a foreign exchange and public health crisis, Ankara delayed the deployment of the system in April. Moreover, Trump indicated that he would hold off on imposing sanctions if Ankara kept the system in storage.
Faced with U.S. sanctions, Ankara chose not to “activate” the S-400. This move was purely symbolic since Turkey had already tested the system against the F-16, stored the S-400 at Akinci Air Base, and trained crews to operate it. However, keeping the missile defense system in storage does not solve the problem. Instead, it merely diminishes the likelihood of Turkey ever receiving the F-35, especially since the decision to use the S-400 is pegged to the whims of Turkish President Recep Tayyip Erdogan.
With Turkey now having taken ownership of the S-400 and would-be Turkish F-35s destined for the U.S. Air Force, the time has come to explore whether it is possible for the two allies to move past this deterioration in bilateral relations. A compromise to manage Turkey’s S-400 operation may not enable Turkey’s return to the F-35 consortium, but it could create a pathway to allow Ankara to purchase the jet later down the road.
Ankara will face a tough decision in a few years: If Turkey no longer has access to the F-35, what aircraft should replace its aging F-16s? It could opt to appropriate money to extend the life of some of its airframes, wait for a costly and economically uncertain effort to produce its own fighter, look to other countries to purchase a front-line fighter, or cobble together some amalgamation of each of these options. The United States has an interest in ensuring that the S-400 is the last piece of Russian defense kit that Turkey buys and that Ankara foregoes the purchase of a second S-400 regiment. From Washington’s perspective, Turkey should have the option to purchase Western fighters and even the F-35 eventually so long as a mechanism is put in place to ensure that the S-400 is not deployed.
The Pakistan F-16 Model
One option the United States should consider is the Pakistan model. Admittedly, it is rare — especially lately — for Pakistan to be held up as a good example of defense cooperation with the United States. Its longstanding ties to insurgent groups in Afghanistan and shadowy nuclear program have bedeviled the bilateral relationship for decades. Nevertheless, there is one area where Pakistan has been, in many respects, a model foreign customer, and that is in its F-16 program.
Pakistan’s 85 F-16s are a source of national pride and position the Pakistan Air Force among the world’s elite. The origins of the program date back to 1981 when, in the aftermath of the Soviet invasion of Afghanistan, the United States agreed to sell Pakistan F-16s to engage the Soviet and Afghan jets that periodically crossed the border to bomb mujahideen training camps. Between 1986 and 1990, Pakistani F-16s shot down at least 10 Afghan and Soviet jets, helicopters, and transport planes.
In the 1990s, the program fell victim to one of the periodic ruptures in the relationship between Washington and Islamabad. Becoming ever more concerned about Pakistan’s undeclared nuclear program — and having lost interest in Afghanistan after the 1989 Soviet withdrawal — the United States refused to deliver 28 F-16s for which Pakistan had paid some $658 million. Although the United States eventually refunded much of the money, Islamabad harbored deep reservations about what it saw as America’s lack of trustworthiness as an ally.
After 9/11, U.S. attitudes changed again. South Asia was at the forefront of American national security policy and Pakistan was — at least initially — seen as an indispensable partner in the campaign to stabilize Afghanistan. President Pervez Musharraf pledged his support to the U.S. war in Afghanistan, and Pakistan allowed its territory to become the primary resupply route for coalition forces fighting there. The F-16 program benefited from the rapprochement in the bilateral relationship. In the first decade after 9/11, the United States agreed to sell Pakistan 18 advanced Block 52 F-16s for approximately $1.4 billion, as well as targeting pods and electronic warfare pods. It also sold mid-life upgrade kits for 53 of Pakistan’s older model F-16s, which made them essentially as capable as the Block 52 version of the aircraft. Turkey, which also flies the F-16, did the upgrades of Pakistan’s fighter aircraft.
The U.S. decision to deliver advanced versions of the F-16 as well as targeting and electronic warfare equipment to Pakistan did not come without strings. And this is where the Pakistan model may hold the key to resolving the impasse over Turkey and the F-35. When it approved the sale of advanced F-16s to Pakistan and the upgrade of older models, the United States also insisted on an unprecedented level of oversight of the program. In order to protect the technology it was exporting, Washington required Islamabad to accept and pay for the deployment of a U.S. technical security team at the Shahbaz and Mushaf air force bases — the two locations where the advanced F-16s were to be deployed.
One of the authors of this article served in the U.S. Embassy in Islamabad, Pakistan at the time and was involved in this program, making several visits to Pakistani F-16 bases to ensure the required security upgrades were completed before the aircraft were deployed there. Each technical security team is made up of four to five U.S. Air Force personnel and some 30 contractors who keep a round-the-clock watch on Pakistan’s advanced F-16s. In total, Pakistan has around 85 F-16s, 66 of which are older Block 15 aircraft and 19 of which are the more modern Block 52. Most of the Block 15 aircraft have received the mid-life upgrade, meaning they are also subject to technical security team monitoring. The mission of the teams is to ensure that the Pakistan Air Force uses its F-16s as intended, does not modify them or the weapons they carry, and does not share the technology with unauthorized parties. In Pakistan’s case, the latter issue is especially salient, because the air force also flies the JF-17 fighter, which it jointly manufactures with China. On bases where advanced F-16s are present, the United States requires that Pakistan separate them from other aircraft and strictly limit access to the area where they are located.
Despite its behavior in other areas, Pakistan has been a steady partner in its F-16 program. The Pakistan Air Force uses its F-16s extensively to attack militants in its tribal areas and shares cockpit footage of these operations with the United States (which one of the authors was able to view while stationed in Pakistan). The presence of technical security teams allows the United States to monitor how Pakistan uses these jets, since their weapons load is configured differently for air-to-ground and air-to-air operations. Of course, in a national emergency, even continuous monitoring can’t prevent the Pakistan Air Force from using its F-16s in ways the United States doesn’t like. For example, in February 2019 India claimed a Pakistani F-16 shot down one of its jets in a skirmish over the border between the two. Pakistan denies this, claiming a Pakistan Air Force JF-17 downed the Indian plane. The U.S. State Department has expressed concern about the incident, but did not directly accuse Pakistan of using its F-16s against India. Instead, it admonished Islamabad for moving some of its F-16s to bases not approved by the United States, indicating that both sides would prefer to let the issue rest. This incident highlights a limitation on all U.S. oversight of military equipment it sells to foreign partners, not just Pakistan. When national survival appears to be at stake, U.S. partners will not be deterred by admonitions to use weapons only for certain missions or against certain threats. This needs to be considered early in the process, before an export license is issued.
Since the lifting of U.S. sanctions on Pakistan after 9/11, the United States and Pakistan have jointly invested some $3 billion in the F-16 program, and despite the irritants elsewhere in the bilateral relationship, cooperation between the two air forces remains robust. Pakistan also cooperates with countries that fly the F-16, including Italy, Jordan, and Turkey. It accepts the intrusive inspection regime of the technical security teams without complaint, and to this point the teams have not registered major violations of the technology security regime they have put in place. Indeed, in the experience of one of the authors, the technical security teams have been a confidence-builder and a shock-absorber in what is otherwise an unstable bilateral relationship. At least in part because of the personal relationships formed between American team members and Pakistan Air Force officers, the U.S. military contingent in the embassy has a better relationship with the Pakistan Air Force than the army or navy. The extensive cooperation between the Turkish and Pakistani air forces — including periodic exercises and the mid-life upgrades of Pakistani F-16s — means that Turkey is familiar with technical security teams and their role in protecting advanced U.S. technology.
Pakistan and Turkey have one more thing in common: The only thing more difficult than partnering with them is dealing with the consequences when the partnership falls apart. As frustrating as Islamabad and Ankara are as partners for the United States (the inverse, by the way, is also true), they are a greater danger to U.S. interests as adversaries. Keeping Turkey on-side as a NATO ally and a customer — if no longer a trusted partner — of the F-35 program is an important American interest, and one that can be achieved with little risk of compromise of U.S. technology.
Finding a Way to Break the Impasse
Turkey’s political decision to not activate the S-400 and to keep it in storage (for now) may have provided a pathway for Ankara to eventually operate the F-35. The United States faces two interrelated challenges that it now needs to manage. The first is that Congress is eager to see the president enforce the Countering America’s Adversaries Through Sanctions Act and is pushing to sanction Turkey for the S-400 purchase. The second is that Ankara has already taken ownership of the S-400, so the United States would have to verify the non-use of the system, perhaps as part of a broader arrangement that could allow for Ankara to take ownership of the F-35.
This approach would require lifting elements from the Pakistan F-16 model and repurposing it to manage the S-400 issue. The U.S-Turkish relationship has been beset by mistrust over the past half-decade, linked to divergent views on the threats emanating from Syria and the choice of partners to fight the Islamic State. Turkish politics have also become more authoritarian, with the ruling Justice and Development Party more dependent than ever on nationalist forces within the country that view the United States and Europe as a threat to Turkish national security.
The problem is how to verify that Ankara does not activate the S-400. To begin negotiations and overcome mistrust, Turkey and the United States should pursue confidence-building measures, such as a bilateral, one-day conference focused on the threat of Russian surface-to-air missiles and the freezing of Turkish-Russian negotiations for a second S-400 regiment. This symposium could be labeled as a technical working group, which is a proposal Ankara has floated to address the S-400 issue with Washington. The meeting could focus on an exchange of data about the S-400 and other surface-to-air missiles, perhaps including the Pantsir system that Turkish drones have had some success against in Syria and Libya. This mechanism would allow Erdogan to communicate to his own base that the United States had capitulated to a key demand, giving him space to sell a compromise with Washington. In truth, Erdogan’s control over Turkish politics is near complete, so he has the flexibility to frame issues as he sees fit and can make concessions if he directs his government to do so.
This symposium could serve as a catalyst to reach a broader agreement on the S-400. The Russian missile system is easily identifiable from space and usually deployed on concrete pads that make them easy to spot with satellite imagery. One potential solution would be for Ankara to declare that Akinci Air Base will be the only deployment location for its S-400 regiment. The two sides could then work out an arrangement to monitor this declaration with open-source satellite imagery, collected each day and shared between the two parties to avoid classification issues. This mechanism would then be augmented with periodic site visits to verify the satellite imagery — a requirement that Congress is certain to demand before approving a major weapons sale to Turkey — beginning with the approval of exports to support a Turkish F-16 life-extension program.
As an added confidence-building measure, Turkey could provide the United States with a complete list of S-400 equipment by serial number. During site visits, U.S. inspectors could inventory the equipment to ensure it remains in storage. The goal here would be to inventory 100 percent of the S-400 equipment each year — a practice that would verify that the deployment site is not changed in secret and allow the United States to learn a bit more about a system it trains to defeat (an outcome Russia would almost certainly object to). Moscow, however, charged Turkey more for its S-400 than either India of China, a decision that appears to have built in the risk that Ankara could someday cancel the deal because of Western pressure. In any case, since the United States already does this with sensitive military equipment it provides to foreign partners (including Turkey), the Turkish armed forces will be familiar with this requirement.
After a set number of visits, Turkey could be allowed to purchase the F-35 as a foreign customer. The six F-35s that were initially slated for Turkey but are now being stored in the United States could be sent quickly to the Turkish Air Force after training is completed. Ankara should also be expected to welcome a U.S. technical security team at Malatya Air Base, where the Turkish Air Force had made the necessary upgrades to stand up its first F-35 squadron. This approach could be used to ensure that Ankara protects the aircraft’s technical secrets, perhaps even during a selected period of time where it could perform routine tests of the S-400 radar. In this scenario, Ankara could have windows of time to perform operative tests, or keep trained S-400 crews current, leaving the work to the U.S. teams embedded at Malatya to verify the non-flight of F-35s on days when the S-400 is active. American personnel could also review the F-35 logs to check for S-400 radar emissions to further verify that the two systems were not operated at the same time. This would be an arduous process for the Turkish Air Force, but it is the reality that Ankara now faces.
This proposed arrangement is dependent on Ankara being willing to countenance an intrusive American presence at a Turkish Air Force base. It also would do little to convince Congress on the necessity of using Turkey as an example to deter other states from purchasing military equipment from Russia. However, it could provide a way forward for Ankara to receive the F-35 and, under tightly circumscribed terms, save some face and claim to operate both the S-400 and F-35. This would not be technically true, but could be used as a means for Ankara to sell a compromise with Washington. This arrangement would advance U.S. strategic and commercial interests — Turkey would buy American fighter aircraft, the F-35 would be protected from exploitation, and Ankara would be unlikely to buy additional Russian defense equipment.
Pakistan was once described as “the ally from hell.” Even as Washington provided it more than $30 billion in aid after 9/11, Pakistan gave sanctuary to the Taliban and supported the Haqqani Network. Nevertheless, the United States was able to sell the Pakistan Air Force F-16s under strict end-use conditions. Washington should take a similar approach to Turkey — a problematic, but key NATO ally with whom it shares a number of interests.
Turkey and the United States have significant political differences over events in the region, but the health of NATO collective defense matters more than bilateral spats between two longtime allies. Ankara risked the security of the F-35 program with its S-400 purchase. There is a pathway to try and overcome this issue, but it will require creative thinking to verify the non-deployment and highly circumscribed use of the S-400. The Pakistan F-16 model is a realistic option and could provide a way to overcome a problem that can be solved with a mixture of technical cooperation and an onsite presence.
Aaron Stein is the director of research at the Foreign Policy Research Institute.
Robert Hamilton is a Black Sea fellow at the Foreign Policy Research Institute and the professor of Eurasian studies at the U.S. Army War College.
Correction: A previous version of this article stated that India claimed a Pakistani F-16 shot down one of its jets in February 2020. That was incorrect. The incident occurred in February 2019.