US sources: Amid Russia tensions producing F-35 fighter jets without Turkey possible
The United States and other NATO allies who own F-35 fighter jets fear the radar on the Russian S-400 missile system will learn how to spot and track the F-35
US to Turkey: No F-35 only if it buys Patriot missiles and not S-400
The US concerned for compromise of F-35’s security if Turkey buys the S-400 missile system
U.S.-Turkey relations headed toward perfect storm
Any country that attempted to buy S-400 systems would face sanctions, but the sanctions to be imposed on Ankara will be much more severe