They are the planes the Ukrainians know how to fly.
The reports are that Biden personally killed the transfer. I can see wanting to do it differently. But to say no outright will be read by Putin as weak. It's how I read it too.
He's not really leading if he's the one slowing the response because he's afraid of World War 3. That is exactly how Putin wants him to think. It's his calculation. Biden has not broken free.
Putin only responds to power.
Yes, Obama was rubbish versus Putin. Even Bush-Cheney would have been better than either Obama or Biden in this situation.