In reality, there is one kind of justice for the great powers and another for weaker states, and neither Moscow nor Beijing would ever face Western military intervention even if they were crushing non-violent protests by their own people, let alone drowning an armed revolt in blood.
But we are dealing here with the nightmare fantasies of regimes that secretly know they are illegitimate. They never acknowledge it in public, and they don't discuss it directly even in private. But they know it nevertheless, and they understand that illegitimacy means vulnerability.
It doesn't matter that Russia or China can simply veto any UN resolution that is directed against them. It makes no difference that no sane government in the rest of the world would commit the folly of sending troops to intervene in either of these giants. Paranoid fears cannot be dissolved by the application of mere reason.
The Russian and Chinese vetoes on the Security Council give them protection from foreign military intervention, but they still worry about it. And they look with horror at the phenomenon of non-violent revolutions that has been removing authoritarian regimes with such efficiency, from the ones that overthrew Communist regimes in Eastern Europe and almost overthrew the Chinese regime in 1989 down to the Arab ones of today.
Now, in Syria, they see both of these threats coalescing.
First, for eight months, they watch strictly non-violent protests - despite some thousands of killings by the Syrian state - undermine the Assad regime. Then, when some of the protesters start fighting back and the regime responds with even greater violence, bombarding city centres and committing massacres of villagers, they hear the Western powers begin to talk about their "responsibility to protect", with the implication that they are contemplating direct military intervention in Syria to stop it.
So Russia and China will veto any Security Council resolution that condemns the Assad regime, and certainly any resolution that hints at military intervention.
Assad must survive, not because he buys Russian arms and gives Russia a naval base in the Mediterranean, but because his overthrow would be a precedent that, they imagine, might one day be used against them.
Utter nonsense but it means that the Russians, in particular, will go on taking the blame for the UN's immobility and lending cover to the West's pretence that it would act against Assad if only the Russians would get out of the way. They will protect Assad right down to the bitter end - and it may be very bitter indeed.
Gwynne Dyer is a London-based independent journalist whose articles are published in 45 countries