President Donald Trump is expected to throw his support behind a possible sale of F-35 stealth fighter jets to Turkey during the NATO summit in Ankara, a move that could reopen one of the most sensitive defense fights between Washington, Ankara and Jerusalem.

The potential shift would mark Trump’s biggest gesture yet toward Turkish President Recep Tayyip Erdogan, but it is not a done deal. U.S. law and Congress still stand in the way, and the central obstacle remains Turkey’s Russian-made S-400 air defense system. Washington removed Ankara from the F-35 program after Turkey bought the system, warning that the Russian platform could expose sensitive data about America’s most advanced fighter jet.

One possible workaround now being discussed is for Turkey to send the S-400 to a third country, but no agreement has been sealed. That path could also run into Russia’s weapons-sale restrictions, meaning the reported Trump push may be more of a political signal than an immediate transfer of aircraft.

Israel is sounding the alarm. Prime Minister Benjamin Netanyahu has publicly urged Washington not to provide Turkey with F-35s or even fighter-jet engines for Ankara’s KAAN program, warning that such a move could “upset the power balance” in the Middle East. For Jerusalem, this is not just another NATO arms deal. It goes straight to Israel’s air superiority, one of the pillars of its regional deterrence.

Netanyahu’s concern is sharpened by Erdogan’s record. Turkey is a NATO member, but Erdogan has repeatedly attacked Israel, aligned rhetorically with Hamas, threatened regional rivals and sought a larger role from Syria to Jerusalem. In Israeli eyes, handing that government stealth aircraft would not strengthen stability. It would arm a hostile power with one of the West’s most sensitive platforms.

The Trump administration has already moved toward approving more than $700 million in jet engines for Turkey’s KAAN fighter, despite objections from some lawmakers. But the F-35 is a far bigger prize. Vice President JD Vance has said U.S. officials are reviewing whether Turkey has met the legal requirements needed to move forward.