Good question will we again let Turkey get away with it?
"Under 2017 legislation, the administration was supposed to sanction Turkey for purchasing Russia's S-400 missile defense system that could expose U.S. military technology to Russian intelligence. During a private meeting with Senate Republicans, Trump asked for "flexibility" and argued against retaliating after coming under pressure from Erdogan.
It was around the same time Trump met with Erdogan that Erdoğan's bodyguards assaulted peaceful protesters on the streets of Washington with no punishment. Then on March 23, 2018, two days before high level meetings between Secretary Tillerson and Erdogan in Ankara, the Justice Department announced it had dropped all charges against 11 of the 15 members"