Nobody tried to kill Putin

A drone attack hits the Kremlin building. Once again, the world is left wondering "who dunnit?". Was it a false flag attack by a Russian leadership determined to drive a wedge between Ukraine and its allies? Or an attack by Kyiv, or even the United States - or a Russian partisan group? Let's look at the theories that are flying around - and at least discount the one that seems on its face to be a non-starter.