Analysts have suggested that Turkey's national Siper air defense missile system, expected to enter service in the near future, could give Ankara a way out of the S-400 debacle that severely strained its longstanding defense relationship with the United States.

Writing in the Atlantic Council in February 2022, Dania Koleilat Khatib suggested that replacing the Russian S-400 air defense system with the indigenous Siper would not antagonize Moscow as much as dropping it for a U.S. system.

"The Siper solution saves face all around," Khatib wrote. "Most importantly, this solution would remove the main hurdle standing in the way of a strategic relationship between the United States and Turkey."

A more recent article published in January made a similar argument. It went so far as to suggest that Turkey is developing its own comparable system to the S-400 so it can potentially gain readmission into the F-35 Joint Strike Fighter program. Ankara was suspended from that program and banned from buying any of the fifth-generation stealth jets in 2019 after it took delivery of the S-400.

Turkey has repeatedly bragged that its Siper will rival the S-400. Ankara first test-fired it in November 2021. In a subsequent test in December 2022, the Siper successfully hit a target 62 miles away.

However, there is zero indication that Turkey is willing to get rid of its S-400s. As recently as Nov. 22, Turkish Defense Minister Hulusi Akar affirmed that Ankara has "no problems with the S-400" and that the system "is in place and ready for use."

Turkey also maintains that it had no choice but to acquire the S-400 after the U.S. refused to supply Patriot missiles. Turkish President Recep Tayyip Erdogan's security and foreign policy advisor Cagri Erhan repeated that line in a January column. In reality, the U.S. offered to sell advanced Patriot PAC-3 to Turkey in late 2018 if it agreed to cancel the S-400 acquisition. Turkey pressed ahead, insisting that it would only buy Patriots in addition to, not instead of, S-400s. Its stubbornness caused it to lose an opportunity to acquire F-35s and Patriots.

Turkey had earlier rejected potential Patriot sales because it wasn't happy with the price and the level of technology transfers Washington was willing to provide. On the other hand, there is little indication that Moscow has provided Ankara with any substantial technology transfers as part of the $2.5 billion deal. Furthermore, Turkey isn't happy with what Moscow has offered, with one Turkish official calling the Russian proposals "a bit light."

The prospect of Turkey gaining readmission into the F-35 program seems extremely remote given its current trouble in acquiring advanced F-16s from the U.S. as part of a proposed $20 billion deal that faces stiff opposition from Congress.

The U.S. Defense Department and the Turkish Defense Ministry held a second round of talks on the F-35 on Jan. 18, following earlier talks in Ankara. A third meeting is scheduled in Ankara this spring. These talks are likely centered around reimbursing money Turkey paid for the first F-35As it had planned to acquire for its air force rather than any potential readmission.

Erdogan raised the issue as recently as Jan. 29, linking it to the ongoing F-16 talks.

"Regarding the F-16s, we want these from you, but you haven't given them. (Originally, you were going to supply) an F-35, but you didn't keep your word," he said. "Although we paid about $1.4 billion, you gave nothing in return. If you give nothing in return, then there will be a price for that, too."

Some have speculated that Turkey risked so much by insisting on the S-400 so it could have a powerful standalone system that could protect Ankara and other strategically-important parts of the country in the event of another coup attempt. Turkish F-16s infamously bombed the Turkish capital during the July 15, 2016, coup attempt. S-400s that are not integrated into Turkey's air defense networks could prove highly effective against such jets if there was another similar coup attempt.

Even if that was Turkey's real motive for acquiring the Russian system, it could have had other, more viable options.

For decades, Ankara has had a close defense relationship with South Korea. Turkey's T-155 Firtina self-propelled howitzers are based on a South Korean design, as is the upcoming Altay main battle tank.

Seoul has developed its own air defense system called the KM-SAM to replace its upgraded American MIM-23 Hawk missiles, the same kind Turkey still operates. It collaborated with Russia to develop this medium-range system, building an interceptor missile based on the 9M96 used in the S-400 and the S-350E. South Korea reached a deal to export the KM-SAM to the United Arab Emirates as part of a landmark $3.5 billion deal in January 2022.

South Korea would have undoubtedly been delighted to sell Turkey the system. It could easily have given Turkey a standalone system with similar missiles to the S-400 without antagonizing either NATO or the United States and incurring sanctions from the latter.

Seoul's willingness to provide buyers of its weaponry generous technology transfers would also have meant that Turkey could build its own version of the KM-SAM, possibly one that it could even export.

These factors would have made the KM-SAM a better all-around deal for Ankara.

The S-400 acquisition fatally undermined trust in U.S.-Turkey defense relations. And so long as Turkey remains adamant about keeping its Russian missiles, even if just in storage, there will likely be no Siper or other similar outside-the-box solution that can even begin to undo this debacle.