This is not to say Erdogan deserves the disdain demanded by some. Turkey is a NATO ally. The United States should listen to requests from its allies, even the more problematic ones. Selling Turkey jet engines so it can operate its indigenous Kaan fighter jets would be prudent. It would show that the U.S. values its military-to-military relationship with Turkey and sees allies as real partners. It would also encourage Erdogan to support rather than complicate NATO collaboration and stability in the eastern Mediterranean.

Turkey’s fierce rivals, Israel and Greece, would oppose the jet engine sale. But their own possession of F-35s in Israel’s case and pending possession in Greece’s would ensure their continued air warfare advantage over Turkey. This is important because Erdogan is malignant toward Israel, a much more important ally of the U.S.; has ambitions to displace Iran as the regional bully; and continues testing for Greek weakness in territorial tensions.

America’s willingness to listen should not translate into concessions. Erdogan is a paranoid authoritarian. He has transformed a once-dynamic democracy and economic powerhouse into a struggling fiefdom of Islamist authoritarianism. He has had his main political rivals indicted on trumped-up charges. He has unashamedly trampled on free speech while boosting cronyism and corruption. He has also treated the U.S. as an ally of convenience rather than a key partner due mutual respect.

Erdogan proved his scorn for America and its values when, during a May 2017 visit to Washington, he ordered his bodyguards to attack peaceful protesters outside the Turkish Embassy. He has used U.S. citizens, such as Pastor Andrew Brunson, as political hostages, retreating only in the face of sanctions during the first Trump administration. Most relevant to F-35 concerns, Erdogan betrayed the U.S. and Turkey’s other NATO allies when he bought Russia’s S-400 air defense system in late 2017.

That deal made Turkey’s additional purchase of F-35s utterly untenable.

The U.S. and allied militaries rightly fear that if Turkey operates the S-400 alongside F-35s, Russia would gain access to valuable intelligence on the F-35’s electronic and radar signatures. Russia could use that knowledge, or share it with China, Iran, or North Korea, to enable more effective targeting of F-35s in a future war. Trump would thus make a grievous error if he allowed Turkey to buy the F-35 without first relinquishing the S-400.

Trump should care less about Erdogan’s diplomatic friendship than he does about the lives of American aircrews and the viability of American war plans. Selling turkey F-35s would also signal personal weakness in the president, reflecting deferential submission to a foreign leader after years of disagreement. Greece, Israel, and Turkey’s other neighbors would fear that Erdogan might use his new fifth-generation jets against them the moment Trump left office or Turkish-American relations soured.

Vice President JD Vance noted Wednesday that the Pentagon is working through the legal and bureaucratic challenges involved in selling F-35s to Turkey. Congress should not be an idle witness to these deliberations. There is concern on Capitol Hill, reflected in legislation to prevent any F-35 sales to Turkey as long as Ankara retains the S-400 system. The chairmen of the House and Senate armed services committees, Rep. Mike Rogers (R-AL) and Sen. Roger Wicker (R-MS), should make clear to Trump that they will resist any move incompatible with American security. They will find bipartisan support in doing so.

MAKING IOWA HEALTHY AGAIN IN THE GUBERNATORIAL ELECTION

Because that is what an unqualified sale of the F-35 to Turkey would entail: jeopardy to American security. It would mean putting the patronage of an unpredictable, broadly anti-American ally before the security of America and its better allies.

It would be intolerable.