[A. Pole]

So why do you suppose they are joining forces against the US?

If they do it would be for the balance of power. If some day China become the strongest nation it might be USA and Russia "joining forces". Russia, China, France, India, and several other countries desire "multipolar world".

I suspect that "multipolar world" would be better for USA since being the world leader or hegemon is too exhausting and sooner or later leads to ruin.

[TheBigPicture]

So you think they are joining forces to take the pressure off the USA? (Just kidding :o)