Still a Flight Risk: Holding the Line on Turkey’s F-35s
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Testifying before the House Foreign Affairs Committee on June 6, Secretary of State Marco Rubio drew a clear line: under current U.S. law, Turkey cannot rejoin the F-35 program so long as it retains the Russian-made S-400 air defense system. Pressed by Representative Dina Titus on whether Ankara could obtain the fifth-generation stealth fighter, Rubio explained that Turkey forfeited its place by purchasing the S-400 from Russia and that the issue is now governed by statute—specifically provisions of the National Defense Authorization Act (NDAA) and the Countering America’s Adversaries Through Sanctions Act (CAATSA). The administration, he made clear, has no legal authority to act on its own. Rubio is right, and it is good that the law binds the executive here.
But the law answers only half the question. Rubio’s testimony came in response to U.S. Ambassador to Turkey Tom Barrack, who told the Antalya Diplomacy Forum in April that he expected the S-400 dispute to be resolved soon and that, from President Trump’s vantage point, Turkey’s “acceptance into an F-35 program is fine.” Barrack’s comments likely implied that, once the S-400 issue is resolved, Turkey’s path back into the F-35 program should be open. That assumption should worry Washington. It treats Turkey’s possession of the S-400 as the only thing standing between Erdoğan and America’s most advanced fighter.
It is not, or at least it should not be. The S-400 is the legal trigger for Turkey’s exclusion, but it is far from the only—or even the most important—reason Ankara should not fly the F-35. The statute is a floor, not a ceiling. If and when Turkey finally disposes of the S-400, the administration should treat that not as a green light but as the start of a longer test, going beyond what the law requires to lock in the safeguards JINSA laid out in its April 2025 report, Flight Risk: Turkey and the F-35, before readmission. With NATO leaders set to convene in Ankara next month—handing Erdoğan his highest-profile platform yet to press his case—getting that sequence right has rarely mattered more.
No The Law Is the Floor
Turkey was expelled from the multinational F-35 program in 2019, during Trump’s first term, after it took delivery of the S-400. U.S. officials concluded that operating the S-400 alongside the F-35 would hand Moscow valuable intelligence on the aircraft’s stealth characteristics, helping Russian operators detect the West’s premier fighter.
Congress translated that judgment into law. Section 1245 of the FY2020 NDAA prohibits the transfer of F-35 aircraft, parts, technical data, and related support to Turkey. The law allows that restriction to be lifted only if the Secretaries of State and Defense certify that Turkey “no longer possesses” the S-400 and has provided “credible assurances” that it will not acquire similar Russian systems in the future. Additionally, in 2020, Washington sanctioned Turkey’s defense procurement agency under CAATSA. Together, these measures make a sale legally impossible until the S-400 issue is resolved—precisely the point Rubio underscored during his recent hearing.
In the nearly seven years since, Ankara has not complied. The batteries remain in Turkey, inactive but intact, while officials continue floating proposals to “box up” the system rather than remove it. But the statutory test is narrow. The prohibition lifts once Turkey no longer possesses the S-400 and pledges not to acquire a replacement. Clearing that bar would make a sale legal, not wise.
The Problem Runs Deeper Than the S-400
Even if Ankara were to neutralize the S-400 dispute, there remain deeper issues in Turkey’s current behavior that warrant its exclusion. Erdoğan underscored those concerns again this week by lambasting that Israel’s operations in Syria and Lebanon had reached a point where they “also threaten Turkey” and accused Prime Minister Benjamin Netanyahu and his “network of murder” of endangering Turkish security. He also warned that Turkey’s response would be “very clear and very strong” if it believed the rights of Turkey or Turkish Cypriots were violated in the Eastern Mediterranean.
These remarks are not a one-off diatribe of a frustrated world leader. Erdoğan has repeatedly called for Israel’s destruction; cheered and openly backed Hamas, and severed Turkey’s economic and diplomatic ties with Jerusalem. He threatens fellow NATO members Greece and Cyprus, pursues military expansion in post-Assad Syria, and continues dismantling democratic institutions at home—most recently through the judicial annulment of the leadership of Turkey’s main opposition party, the Republican People’s Party (CHP). A leader who behaves this way toward U.S. allies and his own citizens is not a candidate for America’s most sensitive military technology.
Nor is this expansionist impulse Erdoğan’s alone. His coalition partner Devlet Bahçeli has warned that Turkey will “never give up” its claims in the Aegean, while Kemal Kılıçdaroğlu of the opposition CHP has likewise called on Turkey to reclaim its influence across former Ottoman lands. When the governing party, its coalition partner, and the main opposition all speak the language of expansion, Washington should condition the F-35 on conduct rather than promises.
Erdoğan also has a long record of treating alliance commitments as bargaining chips. In 2019 he threatened to block NATO defense plans for Poland and the Baltic states unless the alliance branded the Syrian Kurdish People’s Protection Units (YPG) a terrorist organization, and in 2023 he held up Sweden’s NATO accession until he had secured the U.S. F-16 sale he wanted. That last episode is the cautionary one—Ankara converted alliance leverage directly into advanced American aircraft. If the rift in U.S.-Turkish relations were merely a matter of broken trust, then the F-16 sale should have paved the way to mended ties and Turkish reciprocity. Instead, Erdoğan pocketed the concession and soon escalated his rhetoric and actions against Israel and Greece. Hosting the upcoming NATO summit hands Erdoğan another stage and another opening to press for the F-35.
For now, Washington’s restraint on Turkish behavior appears to rest largely on a personal bond. Asked recently whether Erdoğan’s threats could spark a Turkish-Israeli conflict, President Trump waved the danger off, praising Erdoğan as a strong leader and a friend and predicting that no such clash would occur “as long as I’m president because he respects me.” But no president serves forever, and the F-35 would long outlast any personal rapport. A transfer justified by one leader’s relationship with another is the most fragile kind of assurance—precisely why the safeguards governing Turkey’s readmission must be structural and durable, not personal. Arming such a partner with the F-35 would not temper its behavior; it would reward it.
A Stealth Fighter Is Not a Standard Sale
The risks also compound beyond Turkey’s regional ambitions. The F-35 is a “system of systems” that networks with and multiplies the platforms around it—as Israel has demonstrated in operations against Iran—so its compromise would degrade far more than a single fleet. That is why intellectual-property concerns stemming from Turkey’s continued dealings with Russia and China remain decisive. The same concern led Washington to freeze the sale of 50 F-35s to the United Arab Emirates, a far less contentious partner, even after pledging under the Abraham Accords not to oppose such sales.
Turkey should receive the F-35 only after rebuilding trust, not as a means of rebuilding it. Granting Ankara the alliance’s most sensitive platform before it demonstrates a sustained change of course—at a moment when Erdoğan is consolidating one-party rule and deepening ties with Moscow and Beijing—would invert that logic entirely.
Congress Sees It Clearly
Congress increasingly shares these concerns. Last year, House lawmakers introduced a series of bipartisan amendments aimed at tightening restrictions on arms sales to Turkey. Representative Dina Titus proposed requiring the United States to protect Israel’s Qualitative Military Edge (QME) when considering military sales to Ankara, while Representatives Gus Bilirakis and Brad Schneider sought to condition any future F-35 transfer on Turkey ending support for Hamas, ceasing military threats against Israel, and halting cooperation with U.S. adversaries.
Arms sales to Middle Eastern countries already undergo QME review to ensure they do not compromise Israel’s ability to defend itself against regional threats. Turkey is exempt because it is classified as a European country—a designation that made sense when Ankara was a reliable Western ally. It makes far less sense today, as Erdoğan threatens Israel’s destruction while threatening military expansion at the expense of Greece and Cyprus. Taken together, the amendments reflect growing bipartisan skepticism that Turkey should regain access to America’s most advanced military technology absent a significant change in behavior. Notably, many of these proposals mirror recommendations JINSA advanced in Flight Risk, including conditioning future transfers on Turkish behavior and extending QME-style scrutiny to high-end arms sales to Ankara.
Bottom Line
The downstream effects of admitting Turkey on the cheap—treating S-400 removal as the finish line—would reach well beyond Ankara. Israel, Greece, and Cyprus would conclude that Washington rewards coercion with advanced weapons. Moscow and Beijing would draw a similar lesson—that American resolve bends under pressure—while Erdoğan, having pocketed the F-35, would press for the next concession rather than moderate.
Rubio is right that the law forbids a sale today. The more important question is what happens if Turkey ever removes the S-400. Here the administration should set the bar well above the statutory minimum. Washington should hold to a clear standard: no F-35s for Turkey until it has permanently removed its S-400s and forsworn comparable Russian systems, normalized relations with Israel, ended all support for and fundraising by Hamas, established a deconfliction mechanism with Israel over Syria, and ceased its threats against Greece and Cyprus. High-end U.S. arms sales to Turkey should likewise be subject to the same QME standard that governs sales elsewhere in the region.
None of this means slamming the door on the relationship. Washington can pair a firm “no” on the F-35 with a genuine “yes” to Turkey’s legitimate defense needs as a NATO ally—through F-16 sales and, if Ankara removes the S-400, a renewed Patriot offer conditioned on the batteries remaining in Turkey rather than deploying to Syria.
There is even a face-saving exit on the S-400 itself. Turkey could sell the batteries to a third country. India, which Washington already exempted from sanctions for its own S-400 purchase, is a plausible destination acceptable to Ankara, Moscow, and Washington alike. That would satisfy the legal requirement that Turkey no longer possesses the system while allowing Erdoğan to recoup part of the investment.
Turkey will remain a major regional power with or without the F-35, and a more constructive relationship with Ankara remains a worthy goal. But it cannot be purchased by handing America’s most advanced fighter to a leader who buys Russian missiles, embraces Hamas, and threatens U.S. partners. Rubio has held the line on the law. The administration’s task is to hold it higher—and not mistake the absence of an S-400 for the presence of a trustworthy ally.