I doubt this will last. Russia and China have always had a love-hate relationship, and there are several reasons for this.
1) Russians are a nationally a bit bipolar. They want to be thought of as Europeans, but as soon as they behave like Europeans they continually fantasize about their Asian half. And vice versa. Too much Asian and they fantasize about Europe. N.B.: the saying is that when a Russian behaves like and Asian, you can believe him; when he behaves like a European, he is lying.
2) For the better part of 1000+ years, China has been periodically invaded at about 200 year intervals, mostly from the North, and they were sometimes conquered. So they are always nervous about relations with the North. And it’s a prime reason for them to cling to Tibet, and to want to grab Mongolia. As buffers.
3) China’s industrialism is burning itself out, because they have no self control and assume that too much is not enough. Their pollution is out of control, and their response is to make more of it. Sure, they might get a huge new supply of fuel out of this, but it will just make things worse.
Wasn’t it 1984 that had 3 world powers that regularly flip-flopped in their alignments?
Nah. Our stupid detente however shaped China to be far less independent than a Israel that the Soviets felt truly betrayed by. China is in Russia’s pocket because the NWO police imperial hoax is making us more dependent on “good behaviors”
Siberian natural gas will help with China’s pollution problem, since it will burn less coal.
For point 2 — why does Tibet safeguard China? It’s in the south-west, not the north.