Before the week was out, however — and after Risch had briefed a group of reporters about the meeting and his decision — it had become clear that Erdoğan would not change course.

On top of that, a US official told CNN that the Turks tested the S-400 about two weeks ago and “believe” they may have used their F-16s as simulated targets.

It was a move that enraged Risch.

“They actually did some testing, particularly as that testing affected our defensibilities,” Risch said.”The party’s over.”

The 67-page bill that was reviewed by CNN has bridged a partisan divide on Risch’s committee, with his staff and the staff of Sen. Robert Menendez of New Jersey, the top Democrat on the panel, working closely on the technical details over the course of weeks. Menendez has repeatedly pressed to move forward on the legislation in the wake of Turkey’s actions.