I actually think Zelensky has proven himself to be a talented...

But then I watched what came before the argument, and it was pretty standard stuff until Zelensky interrupted to lecture Vance after he said something that left the door open to negotiating with Putin.
Starting that argument there, in a language he still struggles with, inside the Oval Office, at a time when the Trump admin is turning him into a scapegoat for mishandling of the war, is just a bafflingly bad decision. I really don't know what he was thinking.