Turkey risks seriously damaging its relations with Russia if it transfers its Russian-made S-400 air defense systems to a third country in an attempt to return to the US F-35 fighter jet program, international relations professor Hasan Unal has warned.

Unal described such a move as one of the biggest mistakes Turkey could make, according to Turkish broadcaster Haber Global.

The professor stressed that the S-400 systems have already undergone testing and remain combat-ready. He considers them essential to Turkey’s defense capabilities, particularly amid growing regional tensions and statements concerning possible preemptive strikes by Greece.

Although Ankara is developing its own air defense systems, Unal believes they have yet to match the capabilities of the Russian S-400. He also linked the renewed debate over Turkey’s participation in the F-35 program to the interests of groups within the country that support purchasing American fighter jets.

The future of Turkey’s Russian-made air defense systems has already become a subject of official discussions.

In late September, Kremlin spokesman Dmitry Peskov confirmed that the possible relocation of the S-400 systems from Turkey remained on the agenda, with relevant work and contacts underway.

Russian Foreign Minister Sergey Lavrov also indicated that Moscow could agree to the transfer of the systems from Turkey to another country, provided the recipient maintained friendly relations with Russia.

The dispute surrounding Turkey’s S-400 acquisition dates back to 2017, when Ankara signed a contract with Moscow for a regimental set of the Russian air defense systems. Deliveries were completed during the summer and autumn of 2019.

Washington demanded that Turkey abandon the Russian systems and purchase American Patriot air defense systems instead. Ankara refused to comply.

In response, the United States expelled Turkey from the F-35 fighter jet program and imposed sanctions on senior figures in its defense industry under the Countering America’s Adversaries Through Sanctions Act (CAATSA).