John Sullivan was America's man in Moscow in the run-up to the Russian invasion of Ukraine.
The former US ambassador is the one who had conversations with Russian officials about trying to prevent a war, but "there was no engagement", he said.
"They demanded security guarantees for Russia but wouldn't talk constructively about security for Ukraine. They never moved beyond their talking points… it was a charade."
When I ask whether the US should work harder at continuing those conversations to try to end the conflict, he tells me that President Vladimir Putin "wasn't interested in negotiating before the war. He's still not interested in negotiating".
Instead, the Biden administration has focused on rallying global support for arming Ukraine and sanctioning Russia, itself shipping billions of dollars of weapons to the country.