Inside a Lockheed Martin hangar in Fort Worth, Texas, six of the world’s most advanced military aircraft are in storage. Among them – pictured below – is an F-35 jet with the tail number 18-0005, painted in the livery of the Turkish Air Force.
That aircraft made its maiden flight on 1 October 2019, flying out of NAS Fort Worth as part of its test program before it was due to be handed over to the Turks, who had paid the United States $1.4bn to acquire an initial six planes, with plans to acquire over 100 further aircraft.
Then, the US government canceled Turkey’s participation in the program, and – in essence – kept the money.

An Air Defense Dispute
The reason? While Turkey was buying the latest US aircraft, it was also busy acquiring the latest Russian anti-aircraft system – the S-400 – paying the Kremlin $2.5bn for four separate missile batteries.
The American fear was and is that by operating both systems, the Turks would either deliberately or inadvertently “teach” the Russians how to detect the F-35. The Pentagon and White House believed that by having NATO’s most advanced aircraft flying around a country armed with Russian anti-aircraft systems, the Russian tech would gradually learn how to spot and engage the F-35 by tracking its signatures at various altitudes and angles, building a picture of how to circumvent the stealth technology with which the plane is equipped.
While Turkey operated the S-400, the Pentagon insisted, it could not have the F-35.
Yet now, to the horror of NATO members and allies, Donald Trump wants to broker a deal: if Turkey sells the anti-aircraft systems, it may just be able to acquire the planes after all.
"I'm going to make them happy"
“I’m going to probably do something that will make them [Turkey] very happy”, Trump said last week when asked about his plans for the NATO summit in Ankara on 7–8 July.
Trump’s reasoning was typically interesting – appearing to credit his Turkish ally, President Erdogan, for not going to war with the United States in defense of Iran. “He was a prime candidate to go into the war with Iran – maybe on the Iran side, because he’s not a big fan of Israel”, said Trump. While there was never any indication that Turkey was, in fact, prepared to defend Iran, the quote nevertheless alarmed several US allies, as it seemed to position the Oval Office as saying that threatened hostility to NATO would be rewarded rather than sanctioned.
The problem, from NATO’s perspective, is that the F-35 dispute is not an isolated argument about procurement. Instead, it is at the heart of a much deeper Turkish ambiguity: Ankara remains inside NATO, enjoys NATO protection, commands the alliance’s second-largest military and occupies some of the most strategically valuable territory in the Western security architecture, but increasingly behaves like an unaligned power sitting somewhere between the West and its adversaries – and that is being generous.
More Than Just a "Difficult Ally"
Turkey is not simply a “difficult ally”. Difficult allies are normal. From the US perspective, for example, France has long been a source of constant frustration for its insistence on strategic autonomy. Hungary, from the EU and NATO perspectives, has caused endless problems over Russia and Ukraine. Germany, for many years, has been dangerously complacent about Russian energy. But however irritating these examples might be to the US, Turkey is in a different category.
For the Turks are not merely dissenting from NATO policy. Instead, Erdogan appears to be building a foreign policy that is explicitly transactional and therefore frequently aligned against the instincts of the alliance to which he belongs.
The S-400 purchase was the most spectacular example of this, but it was not the only one. Turkey has maintained a working relationship with Vladimir Putin even while other NATO members have tried to isolate Moscow. It has delayed or obstructed NATO decisions when it believed its own interests were not being recognized. It held up Sweden’s accession to the alliance, extracting concessions before eventually allowing the process to proceed. It has positioned itself as a mediator in the Ukraine war while declining to sever ties with Russia in the manner expected of most Western allies.
On Israel, too, Turkey has become one of the most hostile voices inside the NATO family. Erdogan’s rhetoric after 7 October went far beyond criticism of Israeli policy. He praised Hamas as a “liberation” movement, accused Israel of terrorism and presented Turkey as one of the leading global voices against Jerusalem. That position is entirely at odds with NATO policy. The United States, Britain, Germany and most of NATO regard Hamas as a terrorist organization and Israel as a key Western-aligned security partner in the Middle East.
This is why Trump’s remarks caused such discomfort. It is not merely that the president appeared to exaggerate Turkey’s willingness to enter a war on Iran’s side. It is that he seemed to treat Turkey’s restraint – its decision not to actively join a conflict against American interests – as something requiring compensation. Which is, by any measure, an extraordinary position for a US president to take. NATO members are not supposed to be rewarded for not siding with Iran. They are supposed to be counted on not to side with Iran in the first place.
Constantinople Still Matters
Yet, despite all of the problems it causes for NATO, Turkey still matters and still holds power in the way that the holders of Constantinople always have. It controls access to the Black Sea through the Bosphorus and Dardanelles. It borders Syria, Iraq and Iran. It hosts important NATO infrastructure. It has played a meaningful role in the Ukraine war, including by supplying drones to Kyiv and helping to broker aspects of the Black Sea grain arrangements.
That is the dilemma. Turkey is too important to lose, but too unreliable to trust without conditions.
For Washington, the question is whether the F-35 can be used as leverage to pull Ankara back toward the Western camp or whether giving Turkey a path back into the program would reward precisely the behavior that created the crisis.
That is the deeper concern, and one that is keeping officials awake in Athens and Jerusalem in particular, the two US allies most threatened by Turkish conduct and rhetoric. Do Greece and Israel want to see Turkey with F-35s? Absolutely not. Yet President Trump, it seems, is not minded to listen.