A special delivery arrived in Turkey's capital Friday: the first batch of equipment for a $2.5 billion Russian S-400 missile defense system. A source tells the TASS news agency that two more shipments are expected by the end of the summer and that Turkish missile operators are being sent to Russia to train on how to use the system, per CNN. The US is likely to bristle at Russia's suddenly closer ties to the US NATO ally. Turkey had inked a deal to buy 100 F-35 warplanes from the US, and that agreement now looks to be in jeopardy. "If Turkey procures the S-400, it will mean they will not receive the F-35. It's that simple," Acting Secretary of Defense Mark Esper said in June, per NPR. "For an alliance member to buy this kind of equipment from Russia is almost unprecedented," writes a defense correspondent with the BBC.
One of the US' issues with Turkey playing both sides in this acquisitions game is that US defense officials don't want the S-400 system in proximity to the F-35 planes, as that could up the risk that the Russians will be able to unmask intelligence on the warplanes. Turkey insists it would keep the two systems separate. Meanwhile, Pentagon analysts fear the S-400 deal is part of a larger plan of Russian President Vladimir Putin to cause strife among NATO allies, per the New York Times. It's now expected that Turkey will be hit by US sanctions for this latest move, via a 2017 act that imposes penalties on nations that buy military equipment from blacklisted entities; Russia is among them. (Read more Turkey stories.)