Fact-check: Does Turkey's purchase of Russia S-400s really threaten NATO jets?

Turkey activated its Russian-made S-400 missile defence system this week, bringing the drawn-out dispute between Ankara and Washington to a head. The United States has long argued that Turkey's purchase of Russia's S-400 missile defence system may allow Moscow to obtain intelligence on US-made F-35 jets employed by NATO, of which Turkey is a member.

See the full article at stlbeacon.org