Biden Still Doesn’t Get Deterrence

No wonder they give him a list of reporters to call on. President Biden was doing fine at his NATO press conference until it was time to leave. Dazzled by the many reporters barking at him as he moved toward the exit, the president took one more question. He called on Christina Ruffini from CBS News. And instantly regretted it. Their exchange was a reminder that Biden has trouble articulating the meaning of deterrence, the function of alliances, and America’s desired end-state in Ukraine.
"Sir," Ruffini said, "deterrence didn't work. What makes you think Vladimir Putin will alter course based on the action you’ve taken today?"

"Let’s get something straight," Biden replied. "You remember, if you've covered me from the very beginning, I did not say that in fact the sanctions would deter him. Sanctions never deter. You keep talking about that. Sanctions never deter."
They don’t? Then why did Biden threaten Putin with sanctions to begin with?