The U.S. government faces significant pressure to reconsider the potential reinstatement of Turkey into the F-35 Lightning II joint strike fighter program, a move that would reverse the 2019 decision to expel Ankara following its acquisition of the Russian-made S-400 Triumf air defense system. While recent diplomatic overtures and signals from the White House suggest a willingness to revisit the partnership, national security experts and regional allies argue that the technical and strategic risks—ranging from the exposure of sensitive stealth sensor data to deep-seated concerns over Chinese-manufactured telecommunications infrastructure—remain unresolved. The debate over whether Turkey should be readmitted to the program centers on whether the removal of the S-400 hardware is sufficient to mitigate broader systemic vulnerabilities within the Turkish defense and digital ecosystem.
The F-35 program, a multinational effort led by the United States, was designed to maintain air superiority through advanced stealth and sensor fusion capabilities. According to the U.S. Department of Defense, Turkey was officially removed from the F-35 program in July 2019 because the presence of the S-400 system on Turkish soil created an unacceptable intelligence risk. The concern, as stated in official U.S. policy briefings at the time, was that the S-400’s radar could potentially collect technical data on the F-35’s stealth signature, effectively compromising the aircraft’s primary defensive advantage. This determination remains a foundational element of U.S. export control policy under the Countering America’s Adversaries Through Sanctions Act (CAATSA), which was utilized to impose sanctions on Turkey’s defense procurement agency, the Presidency of Defense Industries (SSB), in December 2020.
S-400 Disposal and Legal Thresholds for Re-entry
In recent weeks, reports have circulated regarding Ankara’s potential willingness to transfer the S-400 systems to a third party, such as Qatar or the United Arab Emirates, in an effort to satisfy U.S. requirements. This potential shift aligns with the requirements of Section 1245 of the National Defense Authorization Act for Fiscal Year 2020, which stipulates that the transfer of F-35 aircraft to Turkey cannot occur until the Secretary of State certifies that Turkey no longer possesses the Russian-made system. While transferring the hardware might address the literal terms of the legislation, defense analysts argue that the underlying technical risks persist. Because the S-400 components have been present in Turkey for years, the potential for data harvesting during that period remains a subject of intense scrutiny within the Pentagon. Furthermore, the integration of Russian systems into a NATO-aligned air defense architecture creates ongoing interoperability challenges that the U.S. and its partners have yet to resolve.
Regional Security and Ally Concerns
The prospect of Turkey regaining access to fifth-generation stealth technology has met with significant resistance from regional partners. Israel, which maintains a qualitative military edge (QME) doctrine regarding its defense capabilities, has historically expressed concern over the proliferation of advanced strike platforms in the Middle East. Similarly, Greece and Cyprus have cited Turkey’s ongoing maritime and territorial disputes in the Aegean Sea and the Eastern Mediterranean as reasons to oppose any upgrade to Turkish airpower. These concerns are rooted in the belief that the F-35’s long-range strike capabilities could alter the regional balance of power, potentially exacerbating existing tensions with NATO allies who are already wary of Turkey’s assertive foreign policy posture.
Telecommunications and the Chinese Infrastructure Threat
Beyond the S-400, a less visible but equally critical concern involves the integration of Chinese telecommunications equipment into Turkey’s national backbone. Companies such as Huawei and ZTE maintain a significant presence in the Turkish market. According to research from the Atlantic Council, Chinese firms are deeply embedded in the network infrastructure operated by major Turkish providers like Turkcell and Türk Telekom. This creates a potential vulnerability under China’s 2017 National Intelligence Law, which mandates that Chinese organizations support and cooperate with state intelligence work. The U.S. government has previously blocked high-tech transfers to countries where such infrastructure poses a risk to sensitive military data; for instance, the U.S. suspended a $23 billion arms package to the United Arab Emirates in 2021, citing concerns over the country’s adoption of 5G technology from Huawei.
The risk to the F-35 is not limited to the aircraft itself but extends to the entire operating environment. If Turkey were to operate F-35s while its critical digital infrastructure remains tied to vendors subject to Chinese state influence, the security of the jet’s data links and maintenance networks could be jeopardized. As the U.S. continues to urge NATO allies to divest from high-risk vendors—a policy emphasized by the Trump administration’s guidance on defense spending—Turkey’s continued reliance on these systems stands in direct opposition to the Alliance’s broader goals for secure military mobility and cyber resilience. The F-35, while highly secure, requires a trusted network to function at its peak, and operating the platform within a saturated, potentially compromised digital ecosystem introduces risks that may outweigh the benefits of re-integrating a traditional partner.
The next major checkpoint for this policy debate will likely occur during the upcoming NATO ministerial meetings, where defense ministers are expected to discuss the modernization of alliance air defense capabilities and the implementation of secure communications standards. As of now, no official change to the 2019 expulsion order has been finalized or announced by the U.S. Readers interested in the official status of these sanctions and procurement restrictions can monitor the U.S. Treasury Department’s Office of Foreign Assets Control (OFAC) and the Federal Register for any updates or modifications to the current regulatory framework.
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