How the impeachment inquiry has revealed a long and murky campaign to oust a veteran U.S. ambassador

In February, the U.S. ambassador to Ukraine — a 33-year career diplomat who had served presidents of both parties — received a blunt warning.

“Watch your back,” Ambassador Marie Yovanovitch said she was told by Ukraine’s interior minister.

The Ukrainian official relayed that a pair of Florida businessmen and a Kyiv prosecutor with whom Yovanovitch had clashed were working to oust her from the post she had held since 2016, she later told House investigators.