What do the recently-concluded summit between US President Joe Biden and Chinese President Xi Jinping and the summit Mr Biden held with Russian President Vladimir Putin back in June have in common?

At first sight, very little. Russia may have plenty of nuclear weapons, but it is hardly able to challenge US superiority, and American leaders often must struggle to even treat Russia as a peer competitor. And China, of course, is a different proposition at every level, for whatever Beijing does or aspires to do impinges on US policies at every turn.